Needle assisted jet injection administration of testosterone compositions

ABSTRACT

The present invention provides compositions and methods for treating a subject in need of treatment with testosterone, including introducing testosterone into the subject subcutaneously, intradermally, or intramuscularly, from a needle assisted jet injection device.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Patent ApplicationNo. 61/621,298, filed Apr. 6, 2012, U.S. Provisional Patent ApplicationNo. 61/783,444, filed Mar. 14, 2013, U.S. Provisional Patent ApplicationNo. 61/763,395, filed Feb. 11, 2013, and U.S. Provisional PatentApplication No. 61/776,283, filed Mar. 11, 2013, all of which are hereinincorporated by reference.

BACKGROUND OF THE INVENTION

Testosterone is a steroid hormone from the androgen group. In general,androgens promote protein synthesis and growth of those tissues withandrogen receptors. Testosterone is anabolic, meaning it builds up boneand muscle mass. Testosterone has the following structural formula:

The original and primary use of testosterone is for the treatment ofmales who have too little or no natural endogenous testosteroneproduction males with hypogonadism. However, over the years,testosterone has also been given for many other conditions, e.g.,reducing infertility, correcting lack of libido or erectile dysfunction,correcting osteoporosis, encouraging penile enlargement, encouragingheight growth, encouraging bone marrow stimulation, reversing theeffects of anemia and appetite stimulation.

There are several application methods for testosterone, includinghypodermic injections and transdermal creams, gels and patches. However,hypodermic injections tend to be painful, inconvenient, and increase therisk of polycythemia. Transdermal creams, gels and patches are oftenexpensive, cause acne and skin irritation at the site of administration,have poor compliance with daily administration, and fail to provide somepatients with adequate testosterone levels.

Accordingly, an urgent need exists for methods of administeringtestosterone to provide benefits and improvements over conventionalmethods, e.g., hypodermic injections and transdermal creams, gels andpatches, of administering testosterone to patients.

SUMMARY OF THE INVENTION

In one embodiment, the present invention includes an injection device,comprising a housing member having a distal end and a proximal end, achamber disposed within the housing member configured to hold an amountof a preservative-free medicament comprising testosterone, a needleoperatively associated with the chamber and having a length sufficientto deliver the medicament to an injection site at a depth below apatient's skin sufficient to minimize leak-back, a plunger movablewithin the chamber, and a force generating source capable of providingsufficient force on the plunger to eject at least a portion of themedicament from the chamber through the needle in less than about 20seconds.

In another embodiment, the present invention includes a compositioncomprising testosterone enanthate and sesame oil, the testosteroneenanthate being present at a concentration selected from the groupconsisting of about 50 mg/ml, about 75 mg/ml, about 100 mg/ml, about 125mg/ml, about 150 mg/ml, about 175 mg/ml, about 200 mg/ml, about 225mg/ml, and about 250 mg/ml.

In another embodiment, the present invention includes a compositioncomprising testosterone enanthate and sesame oil, the testosteroneenanthate being present at a concentration selected from the groupconsisting of about 50 mg/ml, about 75 mg/ml, about 100 mg/ml, about 125mg/ml, about 150 mg/ml, about 175 mg/ml, about 200 mg/ml, about 225mg/ml, and about 250 mg/ml, wherein the composition is substantiallyfree of testosterone enanthate precipitate.

In another embodiment, the present invention includes a method ofadministering testosterone comprising administering preservative-freecomposition comprising a unit dose of a testosterone or pharmaceuticallyacceptable ester or salt thereof in a pharmaceutically acceptablecarrier subcutaneously to a mammal, wherein after administration, theplasma level of testosterone is maintained between about 200 ng/dl andabout 1800 ng/dl for a Z1 time period.

In another embodiment, the present invention includes method ofadministering testosterone comprising administering a preservative-freecomposition comprising a unit dose of testosterone or pharmaceuticallyacceptable ester or salt thereof in a pharmaceutically acceptablecarrier subcutaneously to a mammal, wherein after administration theplasma level of testosterone is maintained at a therapeuticallyeffective level for a Z2 time period, (e.g., an extended period of timeduring treatment).

BRIEF DESCRIPTION OF THE DRAWINGS

These and other objects, features and advantages of the disclosure willbe apparent from a consideration of the following non-limiting detaileddescription considered in conjunction with the drawing figures, inwhich:

FIG. 1 is a side view of an injection device according to an embodimentof the present disclosure;

FIG. 2 is a cross-sectional view of the injection device of FIG. 1 in asafety state taken along line A-A;

FIG. 3 is an enlarged view of a portion of the cross-section shown inFIG. 2;

FIGS. 4A and 4B are perspective views of a safety member used inconnection with the injection device of FIG. 1;

FIG. 5 is an additional cross-sectional view of the device of FIG. 1 inthe safety state;

FIG. 6A is a cross-sectional view of the injection device of FIG. 1 in aready state;

FIG. 6B is a cross-sectional view of the injection device of FIG. 1 atthe start of an injection state;

FIG. 6C is a cross-sectional view of the injection device of FIG. 1 atthe end of an injection state;

FIG. 6D is a cross-sectional view of the injection device of FIG. 1 in alocked state;

FIG. 7 is an exploded view of an assembly of the needle guard, sleeveand locking ring associated with the injection device of FIG. 1;

FIG. 8 is a perspective view of a needle guard according to anembodiment of the injector of FIG. 1;

FIG. 9 is a cross-sectional view of the cap shown in FIG. 1;

FIG. 10 is a graph showing the pressure within the liquid chamber of anembodiment of an injection device according to the present disclosure,as a function of time;

FIG. 11 is a cross-sectional view of a needle-free jet injection nozzle;

FIG. 12 is a graph illustrating an embodiment of the present disclosurein which serum testosterone demonstrates a peak upon injection andsubsequently decreases to a therapeutically effective level;

FIG. 13 is a table illustrating the mean concentrations of testosteronein mini-pig serum;

FIG. 14 is graph illustrating the serum concentration of testosterone inthe group 1 mini-pigs of FIG. 13;

FIG. 15 is graph illustrating the serum concentration of testosterone inthe group 2 mini-pigs of FIG. 13;

FIG. 16 is graph illustrating the serum concentration of testosteronefor a 0.5 ml auto-injector injection of 200 mg/ml testosterone enanthatein sesame oil;

FIG. 17 is graph illustrating the serum concentration of testosteronefor a 0.5 ml needle and syringe injection of 200 mg/ml testosteroneenanthate in sesame oil;

FIG. 18 is graph illustrating the serum concentration of testosteronefor a 0.5 ml auto-injector injection of 100 mg/ml testosterone enanthatein sesame oil; and

FIG. 19 is graph illustrating the serum concentration of testosteronefor a 0.5 ml needle and syringe injection of 100 mg/ml testosteroneenanthate in sesame oil.

Throughout the drawings, the same reference numerals and characters,unless otherwise stated, are used to denote like features, elements,components, or portions of the illustrated embodiments. Moreover, whilethe present disclosure will now be described in detail with reference tothe figures, it is done so in connection with the illustrativeembodiments and is not limited by the particular embodiments illustratedin the figures.

DETAILED DESCRIPTION OF THE INVENTION

With reference to the accompanying drawings, various embodiments of thepresent invention are described more fully below. Some but not allembodiments of the present invention are explicitly shown. Indeed,various embodiments of the invention may be embodied in many differentforms and should not be construed as limited to the embodimentsexpressly described. Like numbers refer to like elements throughout. Thesingular forms “a,” “an,” and “the” include the singular and pluralunless the context clearly dictates otherwise.

A. Definitions

“Leak back”, as the term is used herein, refers to the leakage ofmedicament out of an injection site during and/or after injection of amedicament.

“Substantially no leak back”, as used herein refers an amount of leakback from an injection, the amount being less than about 0.05 ml or lessthan about 6% of the total volume or less than about 6% of the weight ofthe medicament. In an embodiment, “substantially no leak back” is anamount of leak back at or below an amount that cannot be readilydetected by swiping a finger across the site of injection immediatelyafter the injection has been completed. In an embodiment, “substantiallyno leak back” is an amount of leak back such that the therapeutic effectof testosterone administered by the injection is not materially altered.By way of non-limiting examples, the amount of leak back can bereferenced in a liquid volume of a fluid composition having a specificconcentration of testosterone, or the amount of leak back can bereferred to in terms of amount of testosterone (e.g., mg testosterone)present in the total leak back volume or the number of injectingpatients out of a population that experience leak back.

To “minimize leak back”, as the term is used herein, is to inhibit orprevent the leak back associated with an injection of medicament,including but not limited to reducing the number of patientsexperiencing leak back associated with an injection

A “preservative”, as the term is used herein, refers to compounds knownin the art to be used for the purpose of preserving a pharmaceuticalcomposition, such as a medicament. As used herein, the preservative ispurposefully used to aid in antimicrobial stability and thus possessantimicrobial activity. Substances not typically considered to bepreservatives, or not typically used for preserving other compositions,are not encompassed by this definition.

“AUC” is the area under a curve representing the concentration of acompound, such as testosterone, or metabolite thereof in the blood orplasma or serum of a patient as a function of time followingadministration of the compound to the patient. For example, followingadministration of a testosterone as described herein, the AUC of thetestosterone may be determined by measuring the concentration of it orits metabolite in blood using methods such as liquidchromatography-tandem mass spectrometry (LC-MS/MS), at various timeintervals, and calculating the area under the blood, plasma or serumconcentration-versus-time curve. The concentration versus time curve issometime referred to as the pharmacokinetic profile. Suitable methodsfor calculating the AUC from a drug concentration-versus-time curve arewell known in the art. Therefore, an AUC for testosterone may bedetermined by measuring the concentration of testosterone in the bloodof a patient following administration of the testosterone to a patient.

“Bioavailability” refers to the amount of a compound, such astestosterone, that reaches the systemic circulation of a patientfollowing administration of the compound to the patient and can bedetermined by evaluating, for example, the blood or plasma concentrationfor the compound.

“Bioequivalent,” as the term is used herein, refers to one or more ofconfidence intervals of (a) the maximum concentration of a medicament(e.g., testosterone) in blood plasma of a patient followingadministration of a dose of the medicament to a patient (“C max”) withan injector, (b) the time to reach the maximum concentration of themedicament in blood plasma of a patient following administration of adose of the medicament to the patient with an injector (“T max”), and(c) area under the curve of the concentration of the medicament in bloodplasma of a patient following administration of a dose of the medicamentto the patient with the injector injected medicament (“AUC”) fallsbetween about 80% and about 125% of the measured confidence interval ofthe same medicament delivered by an alternative route.

“Patient” and “Subject” both independently include mammals, such as forexample, humans.

“About” is understood to mean the range of + and −10% of the valuereferenced. However, use of “about” in reference to a value does notexclude the possibility of the referenced value alone. For example,“about 400” is understood to fully support both “400” as well as “360 to440.”

B. Compositions, Methods, and Embodiments of the Present Invention

The present disclosure encompasses injector embodiments and compositionsand methods suitable for use alone or in combination with the injectorembodiments.

I. Injectors

Typical hypodermic syringes utilize the force of one or more of a user'sfingers pushing to deliver an injection. In some embodiments, poweredinjectors of the present disclosure are configured to help a subjectrepeatably and accurately and quickly administer a testosteroneformulation to a preset depth at each injection without the need toutilize such pushing force.

In some embodiments, the powered injector includes an autoinjector, aneedle-free jet injector, or a needle-assisted jet injector(collectively referred to as “injectors”).

Known autoinjector embodiments of powered injectors use an energy sourcethat produces moderate to low pressure in the medicament chamber so thata medicament contained in the medicament chamber is fired at a slowspeed, similar to the pressure and speed from a finger-driven syringe.In contrast, autoinjector embodiments of the powered injectors of thepresent disclosure use an energy source that produces moderate to highpressure in the medicament chamber so that a medicament contained in themedicament chamber is fired at a fast speed and is completely injectedinto a subject in less than about 10 seconds. Other embodiments of thepowered injectors are jet injectors, which can be needle-assisted orneedle-free jet injectors. Jet injector embodiments can be configured tohave an energy source selected to produce a high pressure in themedicament chamber to eject the medicament with sufficient pressure,force, and speed to exit the injector as a fluid jet. As described ingreater detail below, whereas a medicament injected into a subject viaan autoinjector or hypodermic syringe is delivered in a bolus typicallynear the needle tip such that leak back can occur, the medicamentdelivered from a jet injector is sprayed rapidly into the tissue,typically remotely from the needle tip, and typically does not depositthe medicament in a bolus local to a needle tip such that leak back isminimized Needle-free jet injectors use sufficient pressure andinjection speed so that the fluid jet breaks through the outer layer ofthe skin, depositing the medicament thereunder. Needle-assisted jetinjectors can use lower pressures than needle free jet injectors becausethey employ a needle to break through the outer part of the skin, buthave pressures and speeds that are sufficiently high so that themedicament exits the needle tip as a fluid jet.

Some embodiments of the injectors disclosed herein are single-use or-dose injectors, configured to deliver in a single shot the entirevolume of the agent(s) contained within a chamber of the injector orwithin a cartridge contained within the injector. In other embodiments,the injectors are configured to inject only a portion of the contents ofthe injector or a cartridge within the injector and can usedosage-setting mechanisms to enable the selection of the volume ofinjection to be delivered in one shot, or other mechanisms to provide anadjustable dosage. In each of the foregoing embodiments, the injectorcan be pre-filled, or configured to receive a cartridge that has thedosage of medicament. Alternative embodiments are configured to befillable as known in the art.

Injectors provided by the present disclosure may be utilized by patientsto self-inject testosterone formulations. Various aspects of the presentdisclosure relate to self-injection of testosterone formulations by asubject without the aid of a health care provider. In certainembodiments, the injectors use a needle to inject testosteroneformulations into a target tissue of a subject, such as autoinjector orneedle-assisted jet injector embodiments, while other embodiments areneedle-free injectors and thus do not require a needle to injecttestosterone formulations into a target tissue of a subject. In certainembodiments, the injectors may utilize pressure sufficient to delivertestosterone formulations completely and quickly. In certainembodiments, the injectors may utilize sufficiently high pressure todeliver one or more testosterone formulations completely and quickly ina fluid jet.

In some embodiments, powered injectors provided by the presentdisclosure do not require any priming or preparatory step in order toplace them in condition to deliver an injection, thereby reducing oreliminating exposure of the testosterone formulation to the air and/orpremature expulsion of the testosterone formulation from a needle of theinjector prior to the delivery shot. Therefore, the risk of contact withthe testosterone formulation contained in the injector, by the subjector by a non-user of the injectors, is reduced or eliminated.

A suitable injector for use with the present invention includes theinjector shown in co-pending application Ser. No. 61/763,395 entitled“Needle Assisted Jet Injector Device Having Reduced Trigger Force” andSer. No. 61/776,283 entitled “Needle Assisted Jet Injector Device HavingReduced Trigger Force”, the contents of each which are herebyincorporated by reference in their entirety.

Referring to FIGS. 1-5, an embodiment of an injector according to anembodiment of the present disclosure is presented. The embodiment shownin these figures is a needle injector, and depending on the spring usedand delivery conduit, including the needle and injection outlet, can beconfigured as an autoinjector or a needle-assisted jet injector. Thedepicted injector 12 has an outer housing member 14 configured forallowing a user to handle the injector 12 and that substantially housesmost of the components shown in FIG. 2. In some embodiments, outerhousing 14 is formed from two mating portions 14 a, 14 b that can beconfigured to attach to one another by a snap or press fit or by usingadhesives, welding or the like. Housing 14 includes a medicament chamber22 therein that is configured for storing and dispensing one or moreliquid medicaments, such as, for example, a testosterone formulation. Inthe embodiment shown in FIG. 2, medicament chamber 22 is formed in aprefilled syringe 18 that fits within housing 14, but other types offluid chambers can be used, including known types of cartridges that canbe prefilled, refillable, or the like with the medicament(s).Additionally, medicament chamber 22 can be integrally formed withinhousing 14.

In an embodiment, a stopper portion of a prefilled syringe, or otherportion of the prefilled syringe designed to assist in containing themedicament contained within the prefilled syringe, is made of a materialthat is chemically resistant to one or more constituents contained inthe prefilled syringe. In an embodiment, a suitable stopper hasminimized or reduced leachable or extractable material and/or isresistant to one or more of acids, bases, hydrocarbons, oils, lipids,carbohydrates, or oxygen. Non-limiting examples of suitable stoppersinclude physically-modified rubber, chemically-modified rubber, teflon,and teflon-coated materials. In an embodiment, a stopper is comprised ofany material that enhances the stability of the stopper and/or itsfunction for the containment of an oil-based composition, and inparticular, when compared to the function of a standard rubber stopperused to contain the same oil-based composition.

In the embodiment shown, a safety member 80 is located on the proximalend of outer housing 14 and is removably affixed thereto by a pluralityof tabs that extend through matching openings formed in outer housing 14to form a press-fit between safety member 80 and outer housing 14.Safety member 80 is configured to prevent or reduce the likelihood ofunintended firing of the injection device during, for example, shippingor handling of injector 12. Safety member 80 can be removed by a user ofinjector 12 to allow for unrestricted use of injector 12. Alternativeembodiments of the injectors can be constructed without safety member80.

In a further embodiment, a sleeve 16 is housed within and mounted to thehousing 14 and acts as a syringe support member. In some embodiments,the sleeve 16 is configured to hold and position a prefilled syringe 18,carpule or other container of the type known in the art, such as, forexample, a BD Hypak™ prefilled syringe (Becton, Dickinson and Company).One example of a suitable prefilled syringe for use in the depictedembodiments is one which is available in various sizes and volumes, suchas the Becton Dickinson Hypak™. In some embodiments, the glass of thesyringe body can be adhered to the needle. Using a prefilled syringefacilitates handling of the medicament when the injector is assembled,and there is an extensive body of knowledge of how the medicaments keepand behave in a prefilled syringe. In some embodiments, sleeve 16 issubstantially fixed to the housing 12, such as by snaps, an adhesive, aweld, or another known attachment. The prefilled syringe 18 can have acontainer portion 20 that defines in its interior a medicament chamber22, which is prefilled with an injectable medicament such as, forexample, a testosterone formulation. In other embodiments, themedicament container and chamber are provided by other structures, suchas a chamber that can be integral with or held in the housing, needlehub 32, or other injection outlet portion of the injector, for example.At the distal end of the prefilled syringe 18 is an injection-assistingneedle 24. In certain embodiments, the length of needle 24 is less than5 mm. In one embodiment, the length of needle 24 is greater than 5 mm.In one embodiment, the length of needle 24 is less than 10 mm. In oneembodiment, the length of needle 24 is greater than 10 mm. In oneembodiment, the length of needle 24 is less than 20 mm. In oneembodiment, the length of needle 24 is greater than 20 mm. In otherembodiments, the length of needle 24 is about 1 mm, about 2 mm, about 3mm, about 4, about 5 mm, about 6 mm, about 7 mm, about 8 mm, about 9 mm,about 10 mm, or any range determinable from the preceding lengths (forexample, about 4 mm to about 6 mm, or about 8 mm to about 10 mm). Needle24 has an injecting tip 26 configured as known in the art to penetratethe tissue of a patient which, in some embodiments, is the skin. Aneedle bore extends through the needle 24, as known in the art. The boreis in fluid communication with the medicament in the medicament chamber22 and is open at the needle tip 26 to inject the medicament.

At a proximal end of the medicament chamber 22, opposite from the needle24, is a plunger 28 that seals the medicament in the medicament chamber22. In some embodiments, a syringe wall comprises a tubular portionwhich, in some embodiments, is closed at a distal end and open at aproximal end, to define the medicament chamber 22. Plunger 28 isslideably received in the tubular portion. The prefilled syringe 18 isconfigured such that when the plunger 28 is displaced in a distaldirection, the volume of the medicament chamber 22 is decreased, forcingthe medicament out of the chamber 22 and through the bore of needle 24.At the distal end of the medicament chamber 22 is a needle hub portion32 to which the needle is mounted. A syringe flange 35 extends radiallyfrom the proximal end of the syringe wall. In injector embodiments thatuse cartridges, carpules or other containers that define a chamber tocontain the medicament, the needle can be fluidly connected with thechamber in a different manner, such as by connecting directly to thecartridge, carpule, or other container, or by connecting to anotherportion of the injector, such as a housing thereof, by a separate needlehub.

In the embodiment depicted in FIG. 2, the prefilled syringe 18 has asyringe body 36 wherein the flange 35, syringe wall, and hub portion 32is of unitary construction. In some embodiments, the material comprisingthe syringe body 36 is glass, but other materials such as, for example,plastic or metal, can be used in other embodiments. To radially positionthe distal end of the prefilled syringe 18, in some embodiments sleeve16 has a narrowed bore portion 51 that can be configured to abut theoutside of the syringe wall. The narrowed bore portion 51 can be made ofa resilient material, such as an elastomer, or it can be made unitarilywith the rest of sleeve 16, such as by a series of radially-aligned,resiliently-flexible fingers. Additionally, the proximal portion of thesyringe 18 can be held in place by a shock-absorbing device 33, which,in some embodiments, locates the proximal side of the syringe body 36axially, and absorbs shocks from the impact of a sudden firing of theram 60, such as in jet-injector embodiments, which produce elevatedpressures in the medicament chamber 22 or container 20.

A trigger mechanism can also be housed within housing 14. In someembodiments, the trigger mechanism includes an inner housing 54 that canbe attached to the outer housing 14, such as by snaps, an adhesive, aweld, or other known attachment. Trigger protrusions 56 extend inwardlyfrom the proximal end of the inner housing 54 and are resiliently biasedoutwardly. Trigger protrusions 56 are received in a recess 58 of ram 60in blocking association therewith to prevent distal movement of the ram60 prior to the firing of the device. The ram 60 is moved toward thedistal end of the injector 10 by an energy source, which in someembodiments is a compression spring 52, although in other embodimentsother suitable energy sources can be used such as elastomer orcompressed-gas springs, or a gas generator. An example of a compressionspring 52 suitable for use with injectors of the present disclosure is acoil spring. Alternative embodiments can also use other suitable triggermechanisms as known in the art.

In one embodiment, the invention includes a cammed ram assembly asdescribed in U.S. patent application Ser. No. 13/184,229, which ishereby incorporated by reference in its entirety.

A latch housing 64 can be provided exterior to the inner housing 54 toretain the trigger protrusions 56 in the blocking association in therecess 58 to hold ram 60 in the proximal position until firing isactuated. Latch 64 is slideable inside outer housing 14 with respect tothe inner housing 54, in some embodiments in an axial direction, and insome embodiments latch 64 surrounds the inner housing 54. In someembodiments latch 64 is free to move relative to outer housing 14 and isonly secured in place, after the removal of safety member 80, by thepressure exerted thereon by trigger protrusions 56. In several aspects,nothing is present that biases latch housing 54 away from the proximalend of outer housing 14, including springs or the like. Alternativeembodiments can use a medicament container that is shuttled forward whenthe device is activated to pierce the skin with the needle, and someembodiments use trigger mechanisms that are activated by a button onanother part of the injector, such as at the proximal end or on a sideof the housing as known in the art.

The housing 14 can have a needle guard 66 that is movable with respectto the outer housing 14. In the embodiment of the needle guard 66 shownin FIG. 2, the needle guard 66 is in a protecting position, in which theneedle 24 is disposed within the guard 66. A ridge 65 (FIG. 8) abuts aninterior surface of outer housing 14 so as to maintain needle guard 66within housing 14 when needle guard 66 is fully extended into theprotecting position. The needle guard 66 can be retractable, in someembodiments into the outer housing 14, in a proximal direction to aninjecting position, in which the needle tip 26 and an end portion of theneedle 24 are exposed as shown in FIGS. 6B and 6C for insertion into apatient. In some embodiments, the proximal movement of the guard 66 isprevented at the injecting position.

The needle guard 66 can be associated with the latch 64 such that whenthe guard 66 is displaced proximally it slides the latch 64 in aproximal direction to release the trigger protrusions 56 from the recess58: In some embodiments, the latch 64 has a latching portion 68 thatabuts the inner housing 54 in an association to bias and maintain thetrigger protrusions 58 positioned in the blocking association with theram 60 prior to the firing of the injector 12. In some embodiments, whenthe latch 64 is slid proximately by the retracting of the guard 66 tothe injecting position, the latching portion 68 slides beyond theportion of inner housing 54 that it contacts and the trigger protrusions56 flex away from the recess 58 of the ram 60, allowing the triggerprotrusions 56 to move radially outwardly from the recess 58 andtherefore from the blocking association. When this happens, spring 52biases the ram 60 against plunger 28 to move distally in the injector12.

In some embodiments, a cap 110 can be affixable on the distal end of theinjector 12 so as to cover needle guard 66 and prevent accidentaldisplacement thereof during shipping or during handling prior toinjection. Cap 110 can affix to the distal end of outer housing 14 bypress-fit, screw fit or the like. In certain embodiments, cap 110 caninclude a pair of projections 112 extending inwardly (FIG. 9), that forma distally-facing ridge 114. In such embodiments, needle guard 66 can beformed with a pair of radially-extending flanges 67 (FIG. 8) that areconfigured to abut the distal ridge 114 of projection 112 to secure cap110 to injector 12. In some embodiments, the upper edge 116 (FIG. 9) ofcap 110 can abut the distal end of outer housing 14 such that distalridges 114 of projection 112 are held against flanges 67. Thisarrangement of the cap 110 prevents compression of the needle guard 66proximally into the housing, as the cap 110 is juxtaposed between theguard 66 and housing, securing needle guard 66 in the protectingposition to help prevent accidental firing of the injection mechanism.

In some embodiments, cap 110 can be removed from injector 12 by twistingcap 110 relative to housing 14 such that projections 112 are moved outof alignment with flanges 67, which allows the cap 110 to be moveddistally away from needle guard 66. To prevent accidental removal of cap110 from injector 12 due to inadvertent twisting of cap 110, in someembodiments the cap 110 engages the housing 14 and/or the needle guard66 to require an initially elevated force, such as requiring the cap 110to snap away from its closed position before completing the rotation toremove the cap 110. For example, upper edge 116 of cap 110 can beinclined, as shown in FIG. 9 The incline can include a curve, as shown,but generally the edge 116 can have one edge 118 that is higher than theother edge 120. In some embodiments, the distal end of outer housing 14can have a profile that matches that of upper edge 118 of cap 110. Thisarrangement requires deflection of cap 110 to allow for twisting thereofand increases the force necessary to cause cap 110 to twist relative toneedle guard 66. In an alternative embodiment, the cap 110 can have athreaded or cammed association with the flanges 67, or can have anotherarrangement therewith so that the cap 110 is removed by rotating.

Cap 110 can be attached to injector 12 during assembly thereof. This canbe done by properly aligning cap 110 and twisting it relative to needleguard 66 while applying a proximally-directed force thereto such thatprojections 112 move behind flanges 67. Alternatively, flanges 67 can bestructured to be deflectable inwardly by disposing them on acorresponding tab 69 formed on needle guard 66. In such an embodiment,cap 110 can be assembled onto needle guard 66 prior to assembly ofspring 72 thereinto, as spring 72 can interfere with the inwarddeflection of flanges 67. Alternatively, cap 110 can be resilientlydeformable to allow cap 110 to be pressed onto needle guard 66 such thatprojections 112 pass over flanges 67.

In some embodiments, needle guard 66 can be resiliently biased distallytowards the protecting position by compression coil spring 72. Also, theneedle guard 66 can have an axial opening 74 to allow the needle 24 passtherethrough, and which may be sized according to the type of injectordesired. In some embodiments, the construction of the injector 12 allowsa user to push the distal end of the injector 12 against the patient'sskin, pushing the needle 24 into the skin at an insertion location,substantially at the same speed as the injector 12 is pushed into theskin. Once the needle 24 is fully inserted to an insertion point at adesired penetration depth, the trigger mechanism fires causing theinjector 12 to inject the medicament into an injection site.

In some embodiments, such as for subcutaneous injection using aneedle-assisted jet injector, the needle guard 66 can be configured toallow insertion of the needle 24 to a penetration depth in the skin thatis up to about 5 mm below the skin surface. In some embodiments, thepenetration depth is about 0.5 mm, about 1.0 mm, about 1.5 mm, about 2.0mm, about 2.5 mm, about 3.0 mm, about 3.5 mm, about 4.0 mm, about 4.5mm, about 5.0 mm, about 5.5 mm, about 6 mm, about 6.5 mm or any rangedeterminable from the preceding depths (for example, about 0.5 mm toabout 2.0 mm or about 3.5 mm to about 5.5 mm). In another embodiment,the distance by which the needle tip 26 extends past the needle guard 66or the distal surface of the needle guard 66 that contacts the skin isup to about 5 mm. In some embodiments, the distance by which the needletip 26 extends past the needle guard 66 or the distal surface of theneedle guard 66 that contacts the skin is about 0.5 mm, about 1.0 mm,about 1.5 mm, about 2.0 mm, about 2.5 mm, about 3.0 mm, about 3.5 mm,about 4.0 mm, about 4.5 mm, about 5.0 mm, about 5.5 mm, about 6 mm orany range determinable from the preceding depths (for example, about 0.5mm to about 2.0 mm or about 3.5 mm to about 5.5 mm).

In another embodiment, such as for intramuscular injection using aneedle-assisted jet injector, the injector 12 can be configured to allowthe needle 24 to be inserted into the patient to a penetration depth inthe skin, or alternatively beyond the distal surface of the needle guard66, by a distance of up to about 20 mm. In some embodiments, theinjector 12 can be configured to allow the needle 24 to be inserted intothe patient to a penetration depth in the skin, or alternatively beyondthe distal surface of the needle guard 66, by a distance of about 0.5mm, about 1.0 mm, about 1.5 mm, about 2.0 mm, about 2.5 mm, about 3.0mm, about 3.5 mm, about 4.0 mm, about 4.5 mm, about 5.0 mm, about 5.5mm, about 6 mm, about 6.5 mm, about 7.0 mm, about 7.5 mm, about 8.0 mm,about 8.5 mm, about 9.0 mm, about 9.5 mm, about 10.0 mm, about 10.5 mm,about 11.0 mm, about 11.5 mm, about 12.0 mm, about 12.5 mm, about 13.0mm, about 13.5 mm, about 14.0 mm, about 14.5 mm, about 15.0 mm, about15.5 mm, about 16.0 mm, about 16.5 mm, about 17.0 mm, about 17.5 mm,about 18.0 mm, about 18.5 mm, about 19.0 mm, about 19.5 mm, about 20.0mm, or any range determinable from the preceding depths (for example,about 0.5 mm to about 20.0 mm or about 3.5 mm to about 15.5 mm). Otherexposed needle 24 lengths can be selected for jet injection to differentdepths below the skin, with an overall penetration length of betweenabout 0.5 mm and about 20 mm. In these embodiments, the needle guard 66can be configured for retracting from a protecting position, in someembodiments covering the entire needle, to an injecting position, inwhich the desired length of the tip 26 of the needle 24 is exposed.

In an embodiment, the injection device may comprise a collar surroundingthe needle and defining a collar cavity, the collar having a peripheraland forward skin-contacting surface that surrounds, is discontinuous,and is radially spaced from the needle and injection site by an areathat is sufficiently large to allow a patient's skin to move into thecollar cavity to properly position the needle to penetrate the patientfor intradermal delivery of the substance to the injection site to allowspread of the injected substance under the skin while inhibiting orpreventing backpressure within the skin from forcing the substance outthrough the injection site. An example of such an embodiment can befound in U.S. Pat. No. 8,162,886, hereby incorporated by reference inits entirety.

Safety member 80 can be removably affixed to the distal end of outerhousing 14 and can include a body portion 84 and a pair of resiliently-flexible legs 82 extending therefrom (FIGS. 4A and 4B). Legs 82 areconfigured to extend into corresponding holes or slots 15 formed in theproximal surface of outer housing 14 and can be shaped to provide apressure fit within slots 15 to retain safety member 80 on housing 14.The legs 82 can be biased outwardly and can further include tabs 86disposed on the outside surfaces thereof to engage the inside of outerhousing 14 at the location of slots 15 to further the retention ofsafety member 80 onto outer housing 14. In some embodiments, legs 82 areshaped to allow a user to remove safety member 80 from outer housing 14,when injection is desired. In some embodiments, however, legs 82 preventsafety member 80 from becoming accidentally or unintentionally dislodgedfrom its attachment to outer housing 14.

Legs 82 abut (FIG. 3) the proximal-most surface of latching portion 64when properly attached to outer housing 14 to hinder or prevent jostlingor other motion of latching portion 64 in the proximal direction, whichwould cause the injection mechanism to fire. In some embodiments, legs82 are configured in relationship to the housing 14 and the triggermechanism of the injector 12 such that the force necessary for latchingportion 64 to move legs 82 out of slots 15 is sufficient to preventlatching portion 64 from being jostled out of position due to vibrationduring shipping or from acute shock during shipping or handling causedby dropping of injector 12. Alternative safety members can be used toprevent inadvertent firing of the injector 12.

In an embodiment in which the injector 12 is configured as aneedle-assisted jet injector, the spring 72 and the prefilled syringe 18can be configured to jet inject a medicament such as a testosteroneformulation. Thus, the spring 72 applies a force on the plunger 28 thatcan be sufficient to elevate the pressure within the medicament chamber22 to a level high enough to eject the medicament from the needle 24 asa fluid jet. In several embodiments, jet injection is an injection ofmedicament from the needle tip 26 of the injector 12 with sufficientvelocity and force to drive the medicament to locations remote from theneedle tip 26.

Several jet injector embodiments, whether needle-assisted orneedle-free, have an energy source selected to produce a high pressurein the medicament chamber 22 to eject the medicament therefrom withsufficient force and speed to exit the injector 12 as a fluid jet. It isbelieved that jet injectors deliver medicaments rapidly over a widersurface area under the subject's skin, by essentially “spraying” themedicaments into a subject subcutaneously, thereby rapidly exposing agreater surface area of the subject's target tissue to the medicaments.When delivered by an autoinjector, a medicament typically leaves theautoinjector and is deposited locally, since it is not shot remotelyfrom an injection outlet, and is thus delivered in a bolus typicallynear the needle tip of the autoinjector. This is because an autoinjectorrequires additional injection time to deliver an injection intoresistive media, such as tissue, as opposed to delivery into air. Incontrast, embodiments of a powered injector disclosed herein, and inparticular embodiments of a disclosed jet injector, displayapproximately no difference in injection time when injecting intoresistive media versus air. Because the medicament delivered by a jetinjector is essentially sprayed rapidly into the subject's tissue,typically remotely from the needle tip, the medicament does not leavethe jet injector as a single drop or bolus and is thus typically notdelivered to a subject as a bolus local to a needle tip. Therefore, byusing the jet injectors disclosed herein, a medicament can be dispersedinto a subject's tissue more efficiently. Additionally, because jetinjectors deliver medicaments via high pressure and speed, the deliveredmedicaments have a far lower tendency to leak back out of the injectionsite around the needle or injection track. Therefore, leak-back from thedepth the medicament is delivered back toward the injection site, and/orback to the surface of the subject's skin, can be significantly reducedby use of a jet injector. Therefore, when used to deliver one or moremedicaments according to the present disclosure, such as, for example, atestosterone formulation, jet injectors significantly reduce the risk ofexposure to the medicaments outside of the injection site, therebyreducing the risk of exposure to the medicaments to non-users and to thesubject himself, in addition to reliably delivering the entire dose tothe desired depth. Preventing or reducing leak-back is beneficial inimproving compliance by ensuring that the medicament remains at theinjection site at the desired depth. Preventing or reducing leak-backcan also be beneficial to keeping medicaments contained to a singlearea, thereby preventing inadvertent exposure to the subject and/or toother individuals in his vicinity from leak-back to the surface of theskin. Such exposure can include, for example, direct contact with themedicament on the subject's skin or from atomized medicament that mayreach the subject or nearby individuals through the air, or throughanother medium. Additionally, in many cases, patients who use the slowinjection of a hand-powered hypodermic syringe or autoinjector riskremoving the hand-powered injector from the injection site prematurely,before the shot is completed, leading to exposure of the medicamentoutside the patient's tissue. In some embodiments, there issubstantially no leak-back or no leak-back. In other embodiments, thereis no leak-back in about 95% of the injections. In certain embodiments,the amount of leak back is less than about 15% of the total injectedvolume of medicament, and in other embodiments, when used, the amount ofleak back is no more than about 0.05% to about 15% of the total injectedvolume of medicament, about 0.1% to about 12.5% of the total injectedvolume of medicament, about 0.2% to about 10% of the total injectedvolume of medicament, about 0.3% to about 7.5% of the total injectedvolume of medicament, about 0.4% to about 5% of the total injectedvolume of medicament, about 0.5% to about 3% of the total injectedvolume of medicament, about 0.6% to about 2% of the total injectedvolume of medicament, or about 0.7% to about 1% of the total injectedvolume of medicament. In certain embodiments, the amount of leak back isless than about 15% of the total weight of the injected medicament. Incertain other embodiments, the amount of leak back is no more than about0.1% to about 15% of the total weight of the injected medicament, about0.5% to about 12.5% of the total weight of the injected medicament,about 1% to about 10% of the total weight of the injected medicament,about 2% to about 7.5% of the total weight of the injected medicament,or about 3% to about 5% of the total weight of the injected medicament.

In some embodiments, the injector 12 is configured, and the injectionconducted, to deliver a medicament in a manner to prevent orsignificantly reduce leak-back and the risk and incidence of undueexposure of the medicament to the air or to the outside surface of thepatient's skin.

In some embodiments of needle-assisted jet injectors, short needles canbe used to inject medicaments to different parts of the skin, in someembodiments subcutaneously, without any leak-back. Using a needle 24that extends about 2.5 mm beyond the distal surface of the needle guard66, a 27 gauge needle 24, and a pressure in the medicament chamber 22peaking at about 300 p.s.i. and ending at around 100 p.s.i., resultingin a flow rate of about 0.5 mL/sec, 1 mL of medicament can besuccessfully be injected without significant leak-back in about 100% ofthe tested injections as shown, for example, in Table 3 where onlyslight or measurable, but still slight, wetness at an injection site wasobserved. Thus, needle-assisted jet injectors of the present disclosurepermit jet injection of one or more medicaments using a very shortneedle reliably, regardless of the thickness of the patient's skin, age,weight or other factors.

In some embodiments, selection of the type of spring as a power source,adjustment of the force delivered by the spring, and/or the manner inwhich the spring is packaged within the assembled injector can lead to asignificant reduction in the amount of time required to deliver acomplete injection into a subject, a significant reduction m the springforce required to deliver the injection, and a longer shelf-life. Forexample, the spring present in many known auto injectors is configuredso that a typical injection, in the volume range of about 0.8-1.5 ml, iscompletely delivered into a subject in 10-15 seconds. Embodiments of theinjectors of the present disclosure can have their spring configured soas to deliver a complete injection of about 0.8- about 1.0 ml in volumein about 1 to about 5 seconds, in some embodiments in about 2 to about 4seconds, and in some embodiments in about 3 seconds. It is believed thatthis decrease in time will increase patient compliance when embodimentsof the autoinjectors of the present disclosure are used, as less time isrequired to deliver a complete injection and, thus, the patient willexperience less pain.

Additionally, in some embodiments spring material can be selected so asto only allow a decrease in spring force over the stroke length of theinjection as shown. Many known autoinjectors show a decrease in springforce over the course of a single injection of less than approximately20%. In contrast, embodiments of the injectors of the present disclosurecan be configured so that their spring force decreases by at least about25% over the course of a single injection, in some embodiments fromabout 25% to about 50% over the course of a single injection, in someembodiments from about 30% to about 50% over the course of a singleinjection, and in some embodiments by about 50% over the course of asingle injection

Spring material can also be selected, and/or the spring can be set inthe injector, so as to not have the spring in an overly compressed stateduring packaging and shipment of the spring to an end user or patient.This is advantageous because springs that are overly compressed forexpended periods of time become over-stressed and show a loss of forceover time For example, many known autoinjectors are packaged such thatthey spend most of their shelf-life with their springs compressed. Whenpackaged in this manner, such known autoinjectors experience a decreasein spring force over time as the autoinjector sits on a shelf awaitinguse. In contrast, embodiments of the injectors of the present disclosurecan have springs that are made of a material that is sufficientlyresilient so as to lose less force over time as it is compressed, and/orcan have a spring configured in a fully assembled injector such that itis not in a fully compressed state until the time of injection. In thismanner, embodiments of the injectors of the present disclosure lose fromabout 0% to about 15% of their spring force over a typical shelf life.In some embodiments, the injectors of the present disclosure lose fromabout 10% to about 12% of their spring force over a three year shelflife.

In some embodiments of single-shot injectors, injector 12 includes adisabling mechanism, such as a locking element, which can be provided asa locking ring 70 associated with the injection mechanism. As shown inFIGS. 6A-6D, locking ring 70 can be disposed between sleeve 16 andneedle guard 66, and can interact with sleeve 16 and needle guard 66such that the locking ring 70 only permits needle guard 66 to moverelative to outer housing 14 through a single injection cycle. Thisincludes movement from the protecting position (FIG. 6A) into theinjecting position (FIGS. 6B, 6C) and then to return to the protectingposition (FIG. 6D) under the force of compression spring 72. When needleguard 16 returns to the protecting position at the end of the injectioncycle, locking ring is positioned relative to sleeve 16 and needle guard66 such that further movement therebetween is restricted, thus disablingthe injector from further making injections and retaining the needle 24safely within the housing 14 of the injector 12.

As shown in FIGS. 6A-6D, movement of needle guard 66 through one lockingcycle causes locking ring 70 to move relative to sleeve 16 from aninjecting position to a locking position. In the injecting position,locking ring 70 is disposed such that the upper arms 71 of locking ring70 engage a portion of the device that is associated with the medicamentchamber 22, such as, for example, proximal notches 92 formed in theouter surface of sleeve 16. The engagement of upper arms 71 withinproximal notches 92 releasably maintains locking ring 70 in theinjecting position. As shown in FIG. 7, locking ring 70 can be generallyannular in shape so as to surround the medicament chamber 22, eitherdirectly or indirectly, such as by surrounding sleeve 16. Locking ring70 further includes a pair of lower arms 73, each having a tab 74 formedon the end thereof. When locking ring 70 is in the injecting position,tabs 74 are received in slot 95 formed in needle guard 66 such thatneedle guard 66 is slideable through a predetermined distance overlocking ring 70. As needle guard 66 is moved into the injecting positionwith respect to outer housing 14, needle guard 66 slides over lockingring 70 such that tabs 74 reach the end of slot 95 and are depressedinwardly, allowing needle guard 66 to continue to move into theinjecting position. When the injecting position is reached, tabs 74align with holes 96 of needle guard 66, allowing lower arms 73 to returnto their natural position, wherein the upper surfaces of tabs 74 engagean edge of the holes 96, thereby coupling locking ring 70 to needleguard 66.

As needle guard 66 returns to the protecting position, needle guard 66pulls distally on locking ring 70, causing upper arms 71 to release fromproximal notches 92. In some embodiments, upper arms 71 and proximalnotches 92 are formed with mating inclined surfaces such that theinclined surfaces of upper arms 71 engage another portion of theinjector 12 that is associated with the medicament chamber 22, such asby extending into proximal notches 92, but are forced outwardly bydistally-directed movement relative thereto. This configuration allowsthe needle guard 66 to cause locking ring 70 to move therewith and outof the injecting position as needle guard 66 moves distally toward theprotecting position over sleeve 16, which remains stationary.

When needle guard 66 reaches the protecting position, upper arms 71 moveover distal notches 93 formed in sleeve 16 such that the upper surfacesof upper arms 71 engage the upper surface 94 of distal notches 93.Further, in such a position, flange 77 of locking ring 70 abuts surface67 of needle guard to block needle guard 66 from distal motion relativeto locking ring 70. This engagement prevents locking ring 70 from movingproximally with respect to sleeve 16. Because locking ring 70 is coupledto needle guard 66 in this configuration, and because sleeve 16 isattached to outer housing 14, needle guard 66 is locked relative toouter housing 14, and is prevented from being moved back into theinjecting position. This prevents needle 24 from being accidentallyexposed after use of injector 12. Alternative embodiments can use othermechanisms to prevent re-use of the injector or portion thereof. Someembodiments do not employ such a mechanism so that the injector can bereused. In some embodiments, after injection of the medicament,subsequent injection can be prevented automatically and exposure to orcontact with remnants of the medicament that may remain on portions ofthe injector after the injection, such as on a needle tip or jetinjection nozzle, can also be prevented or avoided by the constructionof the injector 12.

Referring to FIG. 11, a distal end of an embodiment of a needle-free jetinjector is shown. The depicted injector can use the systems disclosedherein to fire the injection as described above for the needle injectorembodiments, but instead of a needle, a jet nozzle 202 is used to injectthe medicament into the subject. Nozzle 202 defines a jet outlet 204having a diameter selected for causing the medicament 200 to exit thenozzle 202 as a fluid jet that is sufficiently strong to pierce theouter skin layers and to continue to the desired depth of injection.

In an embodiment, an injector may have one or more indicators that thatinjection of medicament has been completed. In an embodiment, aninjector may have one or more indicators that injection of medicament isongoing. In an embodiment, one or more indicators which independentlyand distinctively indicate that an injection is ongoing and that aninjection has been completed. In an embodiment, a first indicator isdifferent than a second indicator. Indicators can include, but are notlimited to, audible indicators, tactile indicators (e.g., a click or avibration), visual indicators, physical indicators, electronicindicators, or chemical indicators.

Table 1 shows the results of a trial comparing medicament leak-back thatreached the surface of the skin of a subject after injection; data forneedle-assisted jet injectors as compared to hand-driven hypodermicsyringes is presented. The total number of injections for each group inthe trial was 126, and all were administered by a trained health careprofessional.

TABLE 1 Medicament leak-back to the surface of the skin of a subjectpost injection. % = percent of the total 126 injections administered.Injection site assessment post- Needle-assisted jet Syringe andinjection injector needle Site completely dry 89 (71%) 76 (60%) Slightwetness on site 36 (29%) 50 (40%) Measurable wetness, but 1 (0%) 0 (0%)slight (a drop) Considerable wetness at 0 (0%) 0 (0%) injection site

Because jet injectors deliver medicaments rapidly, in some embodimentsin less than about 2 seconds, the amount of time patients must hold theinjector in their tissue is dramatically decreased as compared to aninjection delivered by a typical syringe or autoinjector. It istherefore believed that utilizing jet injectors according to the presentdisclosure will result in increased patient compliance and adherence toinstructions and will therefore result in an increase in correctlyadministered injected doses. Additionally, the speed at which jetinjectors deliver medicaments can further enhance patient compliancewith regular injections as the amount of pain experienced by a patientself injecting a medicament will be minimized and, in many cases, maynot exist.

In an embodiment, encompassed herein are a device and method foradministering a viscous pharmaceutical formulation to a subject. In anembodiment, a method for administering a viscous pharmaceuticalformulation to a subject comprises formulating a pharmaceuticalformulation in the form of a solution or suspension having a viscosityof between about 25 and 2500 cps, providing the formulation in ainjection device that includes a needle having an insertion length ofless than about 10 mm or is needle-free; and administering theformulation from the injection device through an orifice having adiameter of at least about 0.2 mm by jet injection into a subject. Incertain embodiments, the viscosity referenced herein can be a dynamicviscosity which can be measured by a Brookfied viscometer. In otherembodiments, the viscosity referenced herein can be a kinematicviscosity which is determined by using a capillary viscometer in which afixed volume of fluid is passed through a small orifice at a controlledtemperature under the influence of gravity. In certain embodiments, theviscosity is measured at 20 degrees C. In other embodiments, theviscosity is measured at 25 degrees C.

In other embodiments, an injectable carrier including an amount oftestosterone suspended or dissolved therein has a viscosity between 25and 300 cps at room temperature (e.g., 20-25 degrees C.). In certainembodiments, the viscosity is between 90 to 120 cps, in otherembodiments the viscosity is about 110 cps. In other embodiments theviscosity is greater than or equal to about 70 cps.

In certain embodiments, the carrier is coconut oil, soybean oil, sesameoil, castor oil. Other oils include: arachis (peanut) oil, castor oil,cottonseed oil, ethyl oleate, polyoxyethylated castor oil (HCO-60,polyoxyl 60 hydrogenated castor oil, Cremophor® EL), safflower oil, andsoybean oil

In an embodiment, the formulation includes a pharmaceutically suitableoil and is administered from the injection device at a pressure ofgreater than about 50 psi. In an embodiment, the oil is sesame oil.

In an embodiment, the injection device has an injection needle with abore of about 0.3 mm or about 0.5 mm. Other gauges can also havesuitable bores, e.g., 22 gauge, 25 gauge or 27 gauge.

Referring to the graph shown in FIG. 10, numeral 132 represents thepoint in time when an embodiment of injector 12 is fired, and numeral134 represents the point of completion of injection. In someembodiments, injection is completed when the plunger 28 hits the distalwall of the medicament container 20. Numeral 136 represents the initialand peak pressure during the injection, and numeral 130 represents thefinal pressure during the injection. In some embodiments, the spring 72has a linear spring constant and an injection-assisting needle 24 isused to puncture the skin before commencing the injection. The pressureof injection therefore drops substantially linearly from the start ofthe injection 132 until the injection is completed 134 The finalpressure 130 at the end 134 of the injection is sufficiently elevated sothat even at the end of the firing stroke of ram 60, the medicament isstill jet injected, and a very small amount or none of the medicament isdeposited in a bolus around the needle tip 26

In some embodiments of needle-assisted jet injectors, the peak pressure136 during the injection is less than about 1,000 p.s.i., in someembodiments less than 950 p.s i., in some embodiments less than 900p.s.i., in some embodiments less than 850 p.s.i., in some embodimentsless than 800 p.s.i., in some embodiments less than 750 p.s.i., in someembodiments less than 700 p.s.i., in some embodiments less than 650p.s.i., in some embodiments less than 600 p.s.i., in some embodimentsless than 550 p.s.i., in some embodiments less than 500 p.s.i., in someembodiments less than 450 p.s.i., in some embodiments less than 400p.s.i., and in some embodiments less than about 350 p s.i. In someembodiments, at the end of the injection, the pressure 130 applied tothe medicament in the medicament chamber 22 can be at least about 80p.s.i., in some embodiments at least about 90 p.s.i., in someembodiments at least about 100 p.s.i., in some embodiments at leastabout 150 p.s.i., in some embodiments at least about 200 p s.i., in someembodiments at least about 250 p.s.i., in some embodiments at leastabout 300 p.s.i., in some embodiments at least about 350 p.s.i., in someembodiments at least about 400 p.s.i., in some embodiments at leastabout 450 p.s.i., and in some embodiments at least about 500 p.s.i. Insome embodiments, the initial pressure 136 can be about 330 p.s.i., andthe final pressure 130 is about 180 p.s.i. In some embodiments, theinitial pressure 136 is about 300 p.s.i., dropping to around 60 p.s.i.at the end 134 of the injection. Other injection rates are used forother embodiments discussed herein. For example, needle-free jetinjectors can exert an injection pressure in the range of about 4,000p.s.i. or greater. Other embodiments of jet injectors utilize lowerinjection pressures, such as at least about 80 p.s.i. or at least about60 p.s.i. In contrast, known autoinjectors typically use pressures lowerthan 60 p.s.i.

The needles used in some embodiments of both autoinjectors andneedle-assisted jet injectors are between 26 and 28 gauge, and in someembodiments are around 27 gauge. Other needle gages can also be usedwhere the other components are cooperatively configured to produce thedesired injection including, for example, mini-needles. In someembodiments, the components of the injector 12 can be configured to jetinject one or more medicaments to a subcutaneous injection site.

At about room temperature, in a device having a gauge needle asdescribed herein, in embodiments of needle-assisted jet injectors,injection rates are below about 0.75 mL/sec, in some embodiments belowabout 0.6 mL/sec, in some embodiments at least about 0.2 mL/sec, in someembodiments at least about 0.3 mL/sec, and in some embodiments at leastabout 0.4 mL/sec. In some embodiments, the injection rate is selectedfrom below about 0.75 mL/sec, below about 0.7 mL/sec, below about 0.65mL/sec, below about 0.6 mL/sec, below about 0.55 mL/sec, below about 0.5mL/sec, below about 0.45 mL/sec, below about 0.4 mL/sec, below about0.35 mL/sec, below about 0.3 mL/sec, and below about 0.25 mL/sec. Insome embodiments, the injection rate is about 0.05 mL/sec, 0.1 mL/sec,about 0.15 mL/sec, about 0.20 mL/sec, about 0.25 mL/sec, about 0.30mL/sec, about 0.35 mL/sec, about 0.40 mL/sec, about 0.45 mL/sec, about0.50 mL/sec, about 0.55 mL/sec, about 0.60 mL/sec, about 0.65 mL/sec,about 0.70 mL/sec, about 0.75 mL/sec, about 0.80 mL/sec, about 0.85mL/sec, about 0.90 mL/sec, or any range determinable from the precedinginjection rates (for example, about 0.05 mL/sec to about 1.5 mL/sec orabout 0.70 mL/sec to about 0.75 mL/sec). In embodiments ofneedle-assisted jet injectors, injection rates are selected from atleast about 0.2 ml/sec, at least about 0.25 ml/sec, at least about 0.3ml/sec, at least about 0.35 ml/sec, at least about 0.4 ml/sec, at leastabout 0.45 ml/sec, at least about 0.5 ml/sec, at least about 0.55ml/sec, at least about 0.6 ml/sec, at least about 0.65 ml/sec, and atleast about 0.7 ml/sec.

In some embodiments, the injection of the entire amount of medicament iscompleted in less than about 15 seconds, in some embodiments in lessthan about 12 seconds, in some embodiments in less than about 11.5seconds, in some embodiments in less than about 11.0 seconds, in someembodiments in less than about 10.5 seconds, in some embodiments in lessthan about 10.0 seconds, in some embodiments in less than about 9.5seconds, in some embodiments in less than about 9.0 seconds, in someembodiments in less than about 8.5 seconds, in some embodiments in lessthan about 8.0 seconds, in some embodiments in less than about 7.5seconds, in some embodiments in less than about 7.0 seconds, in someembodiments in less than about 6.5 seconds, in some embodiments in lessthan about 6.0 seconds, in some embodiments in less than about 5.5seconds, in some embodiments in less than about 5.0 seconds, in someembodiments in less than about 4.5 seconds, in some embodiments in lessthan about 4 seconds, in some embodiments in less than about 3.5seconds, in some embodiments in less than about 3 seconds, in someembodiments in less than about 2.5 seconds, in some embodiments in lessthan about 2 seconds, and in some embodiments in less than about 1.5seconds. In some embodiments, the medicament injection takes at leastabout 1.0 second, about 1.5 seconds, about 2.0 seconds, about 2.5seconds, about 3.0 seconds, about 3.5 seconds, about 4.0 seconds, about4.5 seconds, about 5.0 seconds, about 5.5 seconds, about 6.0 seconds,about 6.5 seconds, about 7.0 seconds, about 7.5 seconds, about 8.0seconds, about 8.5 seconds, about 9.0 seconds, about 9.5 seconds, about10.0 seconds, about 10.5 seconds, about 11.0 seconds, about 11.5seconds, about 12.0 seconds, or any range determinable from thepreceding times (for example, about 3.0 seconds to about 8 seconds orabout 10 seconds to about 12 seconds).

In some embodiments, injection of the medicament occurs at about 0.1mL/sec, completing an injection of 1 mL in about 10 seconds. Otherinjection rates however, are possible for the alternative embodiments ofthe injectors 12 disclosed herein. For example, in some embodimentsinjector 12 can be configured to deliver a typical flow rate forneedle-free jet injection, which can be about 1.5 mL/second, and in someembodiments injector 12 can be configured to deliver a typical flow ratefor an autoinjector, which can be about 0.5 mL in 0.3 seconds.

Injection rates can be affected by a number of factors such as, forexample, the gauge of the needle used to inject the medicament, theviscosity of the medicament itself, the glide force of the plunger 28 inthe syringe barrel, the temperature of the medicament to be injected,and the temperature of the room in which the injection is administered,as temperature can have a direct effect on viscosity. In variousembodiments, tissue resistance does not impact the rate of injectionembodiments of the injectors of the present disclosure are capable ofachieving. In various aspects, these parameters can be selected andoptimized in order to deliver a volume of injection in a desired manner.Such selection and optimization can be readily performed by a personhaving ordinary skill in the art without undue experimentation.

In an embodiment, an injector may have the capability to heat thetestosterone composition contained therein to thereby reduce viscosityand thereby decrease injection time of the composition containedtherein. In an embodiment, a heating device is an integral part of theinjector. In an embodiment, a heating device is external to theinjector. In an embodiment, a heating device has an optional temperaturesensing controller. In an embodiment, an injector has one heatingdevice. In an embodiment, an injector has more than one heating device.Non-limiting examples of heating methods and/or devices includeelectrical, chemical, and exothermic sources.

In an embodiment, a heating mechanism heats the medicament containedwithin the injector to a temperature above room temperature. In anembodiment, a heating device heats the medicament contained within theinjector to a temperature about 5 degrees C. above room temperature, orabout 10, about 15, about 20, about 25, about 30, about 35, about 40,about 45, or about 50 degrees C. above room temperature (e.g., 20 to 25degree C.). In one embodiment, the heating mechanism is an electronic,chemical or mechanical heating mechanism. In another embodiment, themechanism or method of use includes placing a device proximal to a heatsource (e.g., under a human arm).

In an embodiment, a heating device or mechanism further comprises atleast one indicia that the heating device is operational,non-operational, and/or at the desired temperature. In an embodiment, aheating device has one or more indicia to indicate to the user that thedevice has reached a temperature suitable for dispensation of themedicament from the device. In an embodiment, an indicator is a visualindicator. In an embodiment, an indicator is an audible or a tactileindicator

In some embodiments, a viscous medicament that would otherwise require alonger injection time can still be injected into a subject in the ratesset forth above by varying the gauge of the needle. For example, in someembodiments a 26 gauge needle can be utilized with the needle-assistedinjectors of the present disclosure to inject a viscous material, insome embodiments a 27 gauge needle can be utilized with theneedle-assisted injectors of the present disclosure to inject a viscousmaterial, and in some embodiments a 28 gauge needle can be utilized withthe needle-assisted injectors of the present disclosure to inject aviscous material. In each of the foregoing embodiments, the rates ofinjection are the same as those rates disclosed above. Therefore, byvarying the gauge of the needle according to the viscosity of themedicament to be injected, the rates of injection can be maintained. Insome embodiments, a 27 gauge needle can be utilized with one or moreembodiments of the injectors of the present disclosure to deliver 1.0 mlof an aqueous solution into air in a duration of time from between about1.0 to about 2.0 seconds, in some embodiments between about 1.5 andabout 2.0 seconds, and in some embodiments in about 1.7 seconds. In someembodiments, a 27 gauge needle can be utilized with one or moreembodiments of the injectors of the present disclosure to deliver 1.0 mlof an aqueous solution into tissue in a duration of time from betweenabout 1.0 to about 2.0 seconds, in some embodiments between about 1.3and about 2.0 seconds, in some embodiments in about 1.5 seconds, and insome embodiments in about 1.3 seconds. In some embodiments, a 27 gaugeneedle can be utilized with one or more embodiments of the injectors ofthe present disclosure to deliver 1.0 ml of a viscous solution, having aviscosity equivalent to 10% w/w polyethylene glycol 20,000 in water,into air in a duration of time from between about 1.0 to about 5.0seconds, in some embodiments between about 2.5 and about 5.0 seconds, insome embodiments in about 4.3 seconds, and in some embodiments in about4.0 seconds. In some embodiments, a 27 gauge needle can be utilized withone or more embodiments of the injectors of the present disclosure todeliver 1.0 ml of a viscous solution, having a viscosity equivalent to20% w/w polyethylene glycol 20,000 in water, into air in a duration oftime from between about 10 to about 15 seconds, in some embodimentsbetween about 12 and about 15 seconds, and in some embodiments in about14 seconds.

The cgs physical unit for dynamic viscosity is the poise (P), which ismore commonly expressed in ASTM standards as centipoise (cP). Typically,aqueous solutions at 20° C. have a viscosity of approximately 1 cP Inseveral embodiments, injectors of the present disclosure can beconfigured to produce a flow rate, or a rate of injection, of 0.5ml/second for aqueous solutions having a cP of, or close to, 1.0,through a 27 gauge needle. In several embodiments, injectors of thepresent disclosure can be configured to produce a flow rate, or a rateof injection, into skin of 0.5 ml/second for aqueous solutions having acP of, or close to, 1.0, through a 27 gauge needle.

U.S. Pat. No. 6,391,003, discloses the experimental results of pressuresthat can be successfully applied to a medicament in a glass cartridge,using 26 and 27 gauge needles. Table 2 illustrates exemplary injectionswith different peak pressures that can be used with a needle-assistedjet injector, especially when using a glass, prefilled syringe:

TABLE 2 exemplary injections that may be delivered by a needle-assistedjet injector. Pressure and Time (sec.) to Inject 1 cc Pressure 26 Gaugeneedle 27 Gauge needle 150 p.s.i. 2.1 4.2 200 p.s.i. 1.9 3.9 240 p.s.i.1.7 3.3 375 p.s.i. 1.4 3.1

Alternative embodiments can use higher or lower injection pressures. Forinstance, needle-free injectors may use higher pressures to penetratethe skin without a needle, and autoinjectors will typically use lowerpressures to simulate a hand-powered syringe injection.

II. Other Injectors

In one or more alternative embodiments, the present disclosure relatesto an auto-injector for dispensing a predetermined dosage of amedicament comprising testosterone (e.g., preservative-free), theauto-injector including a housing that is preferably oval or ellipticalin shape such that it is more ergonomic. In these alternativeembodiments, U.S. Pat. Nos. 7,449,012 and 7,794,432 are herebyincorporated by reference in their entirety. The oval shape prevents theauto-injector from rolling off a table or flat surface, while providinga larger surface area for printing user instructions. A cartridgecontainer is disposed within the housing. A cartridge is received withinthe cartridge container. The cartridge has at least one opening thereinand contains a medicament. The medicament is rearwardly confined by aplunger. The cartridge includes a needle assembly to dispense themedicament therethrough. The cartridge is advanced within the cartridgecontainer from a stored position to an operation position where theneedle extends from the cartridge container such that the dose ofmedicament can be administered. An actuation assembly or power packprovides a stored energy source that is capable of being released todrive the plunger within the cartridge to dispense the medicamentthrough the needle assembly into the user and allowing the needle to beaccessible on activation.

Another aspect of the auto-injector of an alternative embodiment is theprovision of a needle cover received within the housing. The needlecover shields the user from inadvertent exposure to the needle after useof the auto-injector providing sharps protection. Theoretically, theoperation of the needle cover is fail safe because the cover will notdeploy until after the needle penetrates the user. During operation, theneedle of the cartridge extends through an opening in the needle coverto permit the dispensing of a dose of medicament. After use of theauto-injector, the needle cover is held in a locked position to preventthe cover from being retracted to expose the needle. According toanother aspect of an alternative embodiment, the needle cover has alocked retracted position prior to activation of the auto-injector, thusmaintaining a compact configuration of the device prior to use.According to another aspect of an alternative embodiment, the actuationforces associated with the auto-injector are not imparted on the needlecover.

In accordance with another aspect of an alternative embodiment, theauto-injector has a first locking assembly that holds the needle coverin the first locked position. The first locking assembly may be locatedon the cartridge container. The first locking assembly may include atleast one locking tooth pivotally connected to the cartridge containeror the needle cover. Each locking tooth releasably engages the needlecover and includes a locking surface constructed and arranged to contacta surface on the needle cover or the cartridge container. Each lockingtooth may be formed as a separate component that is connected to thecontainer or cover. It is contemplated that the locking teeth may beformed as integral parts of the needle cover or cartridge. A springforce of the locking tooth biases the locking surface into contact withthe needle cover. The spring force may be provided by a spring portionof the locking tooth. The spring force may also be provided by aseparate spring assembly biasing the locking surface into contact withthe needle cover. Each locking tooth is preferably pivotally connectedto the cartridge container. Each locking tooth pivots in response tomovement of the cartridge within the cartridge container. It is alsocontemplated that the locking teeth can pivot in response to movement ofthe collet or the power pack. Typically, the locking surface pivots outof contact with the needle cover when the locking tooth pivots inresponse to the movement of the cartridge. The spring force and theforce exerted by the locking teeth on the cartridge are controlled suchthat they negligibly or minimally impede the motion of the cartridgeduring the injection operation to avoid any premature rupturing of thediaphragm within the cartridge and premature administering of themedicament.

In an aspect of an alternative embodiment, the needle cover is springbiased so that the cover is biased outwardly from the housing to coverthe exposed needle after the first locking assembly is released. Inaccordance with another aspect of an alternative embodiment, theauto-injector has a second locking assembly that holds the needle coverin the second locked position. The second locking assembly may belocated on the cartridge container, the outer body or the cover member.The second locking assembly may include at least one locking arm or wingpreferably connected to the cartridge container. Each locking arm isspaced from the cartridge container such that the locking arm can betemporarily compressed against the cartridge container as the needlecover moves from the first locked position to the second lockedposition. Each locking arm has a locking surface to engage the needlecover when the needle cover is in the locked extended position. Eachlocking arm has a thick strut portion and a thin strut portion, whereinthe thick strut portion is outwardly curved and the thin strut portionis inwardly curved. This construction maintains the locking arm in anormal uncompressed state to reduce stress on the cartridge container.This also permits a smooth deployment of the cover member. Furthermore,this arrangement ensures that the thick strut portion will buckle into astable condition. This creates a stronger lock to prevent the covermember from being moved rearwardly to a retracted position. The inwardlycurved nature of the thin strut portion allows the thick portion tobuckle in a controlled manner to a stable condition. Additionally, theoutwardly curved shape of the thick strut portion provides for fail safelocking of the cover member in the extended position. In the event thatthe thin strut breaks, the thick strut portion will still engage thecover member to maintain it in an extended locked position.

The cartridge container of an alternative embodiment may further includeat least one ledge extending outwardly therefrom. Each ledge isconstructed and arranged to engage an edge of an opening in the needlecover to limit the travel of the needle cover with the respect to thecartridge container when the needle cover is in the extended position.When the ledge on the cartridge container engages the edge of theopening, the outward travel of the needle cover is limited. The secondlocking assembly limits the inward travel of the needle cover. Theneedle cover and the cartridge container contain openings formedtherein. When the openings are aligned prior to activation of theauto-injector, user can view the contents of the cartridge through thehousing and the openings. The housing may be transparent or opaque. Whenopaque, the housing may contain an opening that can be aligned with theopenings in the needle cover and cartridge container so that the colorof the medicament may be checked to determine whether or not themedicament is suitable for injection. If the medicament is discolored,the user will know not to administer the medicament. When the openingsare not aligned after operation of the auto-injector, the user is nolonger able to view the contents of the cartridge through the openingsproviding a visual indication to the user that the auto-injector hasbeen used.

Another aspect of an alternative embodiment is the construction andarrangement of the actuation assembly or power pack, which is mountedwithin the housing adjacent to an open end. A release pin or safe pin isremovably attached to the actuation assembly to prevent inadvertentactuation of the auto-injector when the release pin is in place. A pinor stem on the release pin is received within an opening in theactuation assembly to prevent actuation of the auto-injector. Thisopening in the power pack is spaced from the open end of the housingsuch that the opening is less visible to a user prior to administeringthe drug. This arrangement is provided so that user will not orient theincorrect end of the auto-injector against the injection surface of theuser. The power pack is recessed or spaced from the end of the housing,which provides an indication to the user that pressing the power packwill not operate the auto-injector. The recessed nature of the powerpack serves to hide the release pin hole in the power pack when the useris viewing the instructions on the outer body such that the user doesnot confuse the release pin hole with the opening through which theneedle passes for administering the medicament. The release pin includesat least one tab extending therefrom. The tab is compression fit into acomplimentary recess formed in the actuation assembly to prevent theinadvertent removal of the release pin. The tabs also prevent rotationof the release pin such that the user easily recognizes that the releasepin must be pulled in order to be removed.

The actuation assembly of an alternative embodiment includes an outerbody, which is configured to engage the release pin. The outer body isconstructed to be connected to the housing. An inner body is operativelycoupled to the outer body. At least one retention tab on the inner bodysecures the inner body to the outer body. The inner body is capable oflimited movement with respect to the outer body. A collet is operativelycoupled to the inner body. An energy source is operatively connected tothe inner body and the collet. Unlike conventional collets, the colletin the present invention is molded as a single piece. No spacers orother components are provided between the collet and the plunger in thecartridge. This arrangement simplifies construction of an alternativeembodiment. Different sized collets can be produced and installed intothe actuation assembly, such that only the collet needs to altered whendifferent sized cartridges are used or a different sized dosage ofmedicament is to be administered.

III. Medicament Compositions

In certain embodiments, a medicament of the present invention can be anydrug, including testosterone, which can be useful alone or incombination with other embodiments and/or devices encompassed herein. Inone embodiment, the drug is testosterone.

In one embodiment, a testosterone formulation encompassed hereincomprises at least one preservative, and in particular, apharmaceutically-acceptable preservative, and more particularly, apreservative suitable for one or more of intramuscular, subdermal, andsubcutaneous administration. Suitable preservatives include, but are notlimited to, antimicrobial agents, halogenated alcohols, parabens, andphenylmercuric salts. Non-limiting examples of preservatives includephenol, meta-cresol, benzyl alcohol, methyl paraben, propyl paraben,butyl paraben, benzalkonium chloride, chlorobutanol, thimerosal,phenylmercuric acetate, phenylmercuric borate, and phenylmercuricnitrate.

In one embodiment, a testosterone formulation encompassed herein doesnot comprise a preservative or is free of a preservative and inparticular, free of a preservative described above. In one embodiment, apreservative-free testosterone formulation encompassed herein comprisestestosterone enanthate. In an embodiment, a preservative freetestosterone formulation is a unit dose of testosterone or apharmaceutically acceptable ester or salt thereof in a pharmaceuticallyacceptable carrier. In an embodiment, a preservative free testosteroneformulation is a multiple of at least two unit doses of testosterone ora pharmaceutically acceptable ester or salt thereof in apharmaceutically acceptable carrier. In yet another embodiment, thecomposition is free or substantially free of precipitate (e.g.,testosterone enanthate or testosterone cypionate precipitate).

In an embodiment, a testosterone formulation (e.g., preservative-free)comprises at least one viscous carrier. In yet another embodiment, atestosterone formulation (e.g., preservative-free) includes testosteronein oil. In an embodiment, a testosterone formulation (e.g.,preservative-free) includes testosterone in sesame oil.

In an embodiment, testosterone in a composition encompassed herein ispresent in an amount selected from: about 5 mg, about 10 mg, about 15,about 20 mg, about 25 mg, about 30 mg, about 35 mg, about 40 mg, about45 mg, about 50 mg, about 55 mg, about 60 mg, about 65 mg, about 70 mg,about 75 mg, about 80 mg, about 85 mg, about 90 mg, about 95 mg, about100 mg, about 105 mg, about 110 mg, about 115 mg, about 120 mg, about125 mg, about 130 mg, about 135 mg, about 140 mg, about 145 mg, about150 mg, about 155 mg, about 160 mg, about 165 mg, about 170 mg, about175 mg, about 180 mg, about 185 mg, about 190 mg, about 195 mg, about200 mg, about 205 mg, about 210 mg, about 215 mg, about 220 mg, about225 mg, about 230 mg, about 235 mg, about 240 mg, about 245 mg, about250 mg, about 255 mg, about 260 mg, about 265 mg, about 270 mg, about275 mg, about 280 mg, about 285 mg, about 290 mg, about 295 mg, about300 mg, about 305 mg, about 310 mg, about 315 mg, about 320 mg, about325 mg, about 330 mg, about 335 mg, about 340 mg, about 345 mg, about350 mg, about 355 mg, about 360 mg, about 365 mg, about 370 mg, about375 mg, about 380 mg, about 385 mg, about 390 mg, about 395 mg, about400 mg of medicament or any range determinable from the preceding dosageamounts (for example, about 75 mg to about 150 mg or about 100 mg toabout 200 mg). In another embodiment, testosterone is present in anamount greater than about 5 mg.

As will be understood by the skilled artisan, the amounts oftestosterone encompassed herein may be contained within a suitablevolume of fluid (e.g., a suitable carrier or oil), based on the methodof administration and/or the device used for administration, desiredtestosterone concentration, etc., among other things. In an embodiment,the amount of medicament contained in and injected from medicamentchamber 22 can be between about 0.02 mL and about 4 mL, in someembodiments less than about 3 mL. In other embodiments, the amount ofmedicament contained in and injected from medicament chamber 22 can beabout 0.02 mL, about 0.04 mL, about 0.06 mL, about 0.08 mL, about 1.00mL, about 1.02 mL, about 1.04 mL, about 1.06 mL, about 1.08 mL, about2.00 mL, about 2.02 mL, about 2.04 mL, about 2.06 mL, about 2.08 mL,about 3.00 mL, about 3.02 mL, about 3.04 mL, about 3.06 mL, about 3.08mL, about 4.00 mL, about 4.02 mL, about 4.04 mL, about 4.06 mL, about4.08 mL, about 5.00 mL, or any range determinable from the precedingvolumes (for example, about 0.04 mL to about 5.00 mL or about 1.04 mL toabout 3.02 mL). Larger volumes may also be selected depending on theparticular medicament(s) utilized and dosage required. In someembodiments, e.g., in reference FIG. 6A, a pre-filled syringe 18containing the desired amount of medicament is assembled into theremaining parts of an injector 12. In some embodiments, the pre-filledsyringe 18 contains from about 0.02 mL to about 4.00 mL ofmedicament-containing fluid. In some embodiments, the pre-filled syringe18 contains about 0.02 mL, about 0.04 mL, about 0.06 mL, about 0.08 mL,about 1.00 mL, about 1.02 mL, about 1.04 mL, about 1.06 mL, about 1.08mL, about 2.00 mL, about 2.02 mL, about 2.04 mL, about 2.06 mL, about2.08 mL, about 3.00 mL, about 3.02 mL, about 3.04 mL, about 3.06 mL,about 3.08 mL, about 4.00 mL, about 4.02 mL, about 4.04 mL, about 4.06mL, about 4.08 mL, about 5.00 mL, or any range determinable from thepreceding volumes (for example, about 0.04 mL to about 5.00 mL or about1.04 mL to about 3.02 mL) of one or more medicaments.

In one embodiment, an ester form of testosterone is used. In oneembodiment, a testosterone formulation encompassed herein comprisestestosterone enanthate and/or testosterone cypionate, collectivelyreferred to herein as “testosterone”. It is understood that alternativecompounds that include the testosterone moiety are within the scope ofthe term “testosterone”, including active metabolites of testosterone.

In an embodiment, a testosterone formulation encompassed herein is suchthat it can be administered through a fine-gauge needle, the methods ofadministration and the devices for administration encompassed and/ordescribed in detail elsewhere herein. A non-limiting example of a finegauge needle is a 27 gauge needle. However, other examples of fine gaugeneedles are described in detail elsewhere herein. In an embodiment, atestosterone formulation encompassed herein, when administered incombination with device encompassed herein, a dose can be administeredusing a force sufficient to smoothly overcome resistance to flow throughthe syringe body or needle. Methods of determining and optimizing flowrate for injection of a medicament are also described in detailelsewhere herein.

IV. Methods of Treatment

The present disclosure provides, in part, a method, device, andcomposition for treating hypogonadism, reduced infertility, lack oflibido or erectile dysfunction, osteoporosis and anemia, a method forencouraging penile enlargement and height growth, and method ofstimulating bone marrow and appetite.

The concentration of testosterone in the blood stream of a subject willdepend on the amount of testosterone in the composition administered tothe subject as well as the route of administration and the specificformulation used.

In an embodiment, a subject is treated with a single dose of acomposition as encompassed herein. In an embodiment, a subject istreated with two or more doses of a composition as encompassed herein.In an embodiment, a subject is treated with multiple doses of acomposition as encompassed herein. In an embodiment, a subject treatedwith multiple doses is treated for at least one day. In an embodiment, asubject treated with multiple doses is treated for at least one week. Inan embodiment, a subject treated with multiple doses is treated for atleast one month. In some embodiments, a patient is injected weekly orbi-weekly with one or more testosterone doses. The patient ispreferably, but not limited to, being injected in the abdomen or thigh.

V. Pharmacokinetics

In an embodiment, a composition comprising testosterone (e.g., apreservative-free testosterone composition) administered to a subject asencompassed herein provides pharmacokinetics, including systemicbioavailability, that has substantially the same (or similar)pharmacokinetics, including systemic bioavailability, of testosteronewhen the same dose of testosterone is administered to said subject usingneedle and syringe, intramuscularly or subcutaneously. In anotherembodiment, the method of treating hypogonadism as encompassed hereincomprises introducing into the subcutaneous, intradermal, orintramuscular tissue of a subject, from a needle assisted jet injectiondevice, a composition comprising testosterone (e.g., preservative-free)in a dose ranging from about 5 mg to about 400 mg, wherein thepharmacokinetic profile of said testosterone delivered by said needleassisted jet injection device is substantially the same as thepharmacokinetic profile of the same dose of said testosterone whenadministered to said subject via needle and syringe, intramuscularly orsubcutaneously.

As used herein, the values obtained or calculated for measuredtestosterone can be in reference to total testosterone, freetestosterone, bio-available testosterone or serum testosterone.

In an embodiment, testosterone administered in accordance with thedisclosure encompassed herein achieves comparable, e.g., bioequivalence,pharmacokinetic profile by generating C_(max) and T_(max) for the sameperiod of time as compared to when the same dose of testosterone isdelivered via a needle and syringe, intramuscularly, intradermally, orsubcutaneously. In an embodiment, testosterone administered inaccordance with the disclosure encompassed herein achieves apharmacokinetic profile that is superior to that obtained by generatingC_(max) and T_(max) for the same period of time as compared to when thesame dose of testosterone is delivered via a needle and syringe,intramuscularly, intradermally, or subcutaneously.

In an embodiment, a composition comprising testosterone (e.g., apreservative-free composition) administered to a subject in accordancewith the methods disclosed herein provides enhanced pharmacokinetics,including systemic bioavailability, of testosterone when the same doseof testosterone is administered to said subject using one of atransdermal cream, gel or patch or needle and syringe, intramuscularly,intradermally, or subcutaneously. In an embodiment, a method ofadministering testosterone in accordance with the disclosure encompassedherein comprises introducing into the subcutaneous, intradermal, orintramuscular tissue of a subject, from an injector device asencompassed herein and described elsewhere herein, a compositioncomprising testosterone (e.g., preservative-free) in a dose ranging fromabout 5 mg to about 400 mg, wherein the pharmacokinetic profile oftestosterone delivered by the injector device is enhanced relative tothe pharmacokinetic profile of the same dose of said testosterone whenadministered to said subject via one of a transdermal cream, gel orpatch or needle and syringe, intramuscularly, intradermally, orsubcutaneously. In an embodiment, a method of administering testosteronein accordance with the disclosure encompassed herein comprisesintroducing into the subcutaneous, intradermal, or intramuscular tissueof a subject, from a needle assisted jet injection device as encompassedherein and described elsewhere herein, a composition comprisingtestosterone (e.g., preservative-free) in a dose ranging from about 5 mgto about 400 mg, wherein the pharmacokinetic profile of testosteronedelivered by the needle assisted jet injection device is bioequivalentto the reference-listed drug when administered via needle and syringe,intramuscularly, intradermally, or subcutaneously. In anotherembodiment, bioequivalent pharmacokinetic profile of testosteronedelivered by the needle assisted jet injection device is enhanced ascompared to the reference-listed drug when administered via needle andsyringe, intramuscularly, intradermally, or subcutaneously.

In an embodiment of a 5 mg to 400 mg dose of the present disclosure, thepharmacokinetic profile provides a linear increase in testosteroneexposure with increases in dose of testosterone administered. In anembodiment, the pharmacokinetic profile provides dose proportionalincreases in testosterone exposure (AUC and/or C_(max)). In anotherembodiment, the pharmacokinetic profile provides a linear or nonlinearrelationship between AUC (ng*h/ml) of testosterone and dose oftestosterone when the AUC (ng*h/ml) values are plotted against thecorresponding dose values in a Cartesian Plane. In another embodiment,the pharmacokinetic profile provides a linear or nonlinear relationshipbetween C_(max) of testosterone and dose of testosterone when theC_(max) values are plotted against the corresponding dose values in aCartesian Plane. Pharmacokinetic information concerning testosterone anda needle assisted jet injector can also be found in co-pendingprovisional application Ser. No. 61/621298, the content of which ishereby incorporated by reference in its entirety.

Accordingly, one embodiment of the present invention provides a methodof treating hypogonadism in a subject in need of treatment, said methodcomprising introducing into the subcutaneous or intramuscular tissue ofa patient in need of testosterone, from a needle assisted jet injectiondevice, a composition comprising testosterone (e.g., preservative-free)in a dose ranging from about 5 mg to about 400 mg, wherein said methodprovides a pharmacokinetic profile whereby testosterone exposureincreases linearly in proportion to increases in the dose strength (orlevel) of testosterone. In an embodiment, the pharmacokinetic profileprovides an AUC that increases linearly in proportion to increases inthe dose strength (or level) of testosterone administered. In anotherembodiment, the pharmacokinetic profile provides a C_(max) thatincreases linearly in proportion to increases in testosterone dose leveladministered.

For comparison purposes, commercially available testosterone and theassociated medication guides and package insert labels of Androgel 1%(NDA No. 021015), Androgel 1.62% (NDA No. 022309), Testim (NDA No.021454) and Axiron (NDA No. 022504) can be used, and the package insertlabels of each of the foregoing are hereby incorporated by reference intheir entirety.

A. Effective Plasma Levels of Testosterone

In one embodiment, a method of administering testosterone comprisesadministering a composition comprising a unit dose of testosterone(e.g., preservative-free) or pharmaceutically acceptable ester or saltthereof in a pharmaceutically acceptable carrier subcutaneously to amammal, wherein after administration the plasma level of testosterone ismaintained at a therapeutically effective level for a period of time. Inone embodiment, a Z1 time period is the time period for which the plasmalevel of testosterone is maintained at a therapeutically effectivelevel.

In another embodiment, a composition encompassed herein, whenadministered according to the methods and the devices encompassedherein, maintains the plasma level of testosterone at a therapeuticallyeffective level starting at about 1 minute after administration andending at about 1 month after administration. In such an embodiment, acomposition encompassed herein, when administered according to themethods and the devices encompassed herein, maintains the plasma levelof testosterone at a therapeutically effective level starting at about 2minutes after administration, or at about 3 minutes, about 4 minutes,about 5 minutes, about 10 minutes, about 20 minutes, about 30 minutes,about 45 minutes, about 60 minutes, about 2 hours, about 3 hours, about4 hours, about 5 hours, about 6 hours about 7 hours about 8 hours about9 hours, about 10 hours, about 11 hours, or about 12 hours afteradministration, up to about 1 month after administration. In anembodiment, a composition encompassed herein, when administeredaccording to the methods and the devices encompassed herein, maintainsthe plasma level of testosterone at a therapeutically effective levelstarting at about 1 minute after administration and ending at about 25days after administration, about 20 days after administration, about 15days after administration, about 14 days after administration, about 13days after administration, about 12 days after administration, about 11days after administration, about 10 days after administration, about 9days after administration, about 8 days after administration, about 7days after administration, about 6 days after administration, about 5days after administration, about 4 days after administration, about 3days after administration, about 2 days after administration, about 1day after administration, or about 0.5 days after administration.

In one embodiment, a first dose has a first profile and subsequent doses(which may be the same as or different from the first dose) impartdifferent profiles. Depending upon patient response, dose, dose volumeand timing of subsequent dosings, the pharmacokinetic profile of apatient can be customized to meet a particular patient's needs throughthe use of the present invention. In some embodiments, the presentinvention can be used to maintain therapeutic levels of testosteroneduring and/or across a prescribed dosing cycle (e.g., once weekly dosingfor: 2 weeks, 3 weeks, 4 weeks, 5 weeks, two months, five months, ayear, or more).

In an embodiment, a method of administering testosterone comprisesadministering a composition comprising a unit dose of a testosterone(e.g., preservative-free) or pharmaceutically acceptable ester or saltthereof in a pharmaceutically acceptable carrier subcutaneously to amammal, wherein after administration, the plasma level of testosteroneis maintained between about 300 ng/dl and about 1100 ng/dl for a timeperiod, “Z1”

In one embodiment, a composition encompassed herein, when administeredaccording to the methods and the devices encompassed herein, maintainsthe plasma level of testosterone between, e.g., about 300 ng/dl andabout 1100 ng/dl starting at about 1 minute after administration andending at about 1 month after administration. In yet another embodiment,a composition encompassed herein, when administered according to themethods and the devices encompassed herein, maintains the plasma levelof testosterone between, e.g., about 300 ng/dl and about 1100 ng/dlstarting at about 2 minutes after administration, or at about 3 minutes,about 4 minutes, about 5 minutes, about 10 minutes, about 20 minutes,about 30 minutes, about 45 minutes, about 60 minutes, about 2 hours,about 3 hours, about 4 hours, about 5 hours, about 6 hours about 7 hoursabout 8 hours about 9 hours, about 10 hours, about 11 hours, or startingat about 12 hours after administration, up to about 1 month afteradministration. In an embodiment, a composition encompassed herein, whenadministered according to the methods and the devices encompassedherein, maintains the plasma level of testosterone between, e.g., about300 ng/dl and about 1100 ng/dl starting at about 1 minute afteradministration and ending at about 25 days after administration, about20 days after administration, about 15 days after administration, about14 days after administration, about 13 days after administration, about12 days after administration, about 11 days after administration, about10 days after administration, about 9 days after administration, about 8days after administration, about 7 days after administration, about 6days after administration, about 5 days after administration, about 4days after administration, about 3 days after administration, about 2days after administration, about 1 day after administration, or endingabout 0.5 days after administration.

In an embodiment, the plasma level of testosterone is maintained at avalue selected from the group consisting of about 300 ng/dl to about1100 ng/dl, about 350 ng/dl to about 1050 ng/dl, about 400 ng/dl toabout 1000 ng/dl, about 450 ng/dl to about 950 ng/dl, about 500 ng/dl toabout 900 ng/dl, about 550 ng/dl to about 850 ng/dl, about 600 ng/dl toabout 800 ng/dl, about 650 ng/dl to about 750 ng/dl, and about 675 ng/dlto about 725 ng/dl. In an embodiment, the plasma level of testosteroneis maintained at a value selected from the group consisting of about 300ng/dl, about 350 ng/dl, about 400 ng/dl, about 450 ng/dl, about 500ng/dl, about 550 ng/dl, about 600 ng/dl, about 650 ng/dl, about 700ng/dl, about 750 ng/dl, about 800 ng/dl, about 850 ng/dl, about 900ng/dl, about 950 ng/dl, about 1000 ng/dl, about 1050 ng/dl, and about1100 ng/dl. In an embodiment, the plasma level of testosterone ismaintained at a value selected from the group consisting of at leastabout 300 ng/dl, at least about 350 ng/dl, at least about 400 ng/dl, atleast about 450 ng/dl, at least about 500 ng/dl, at least about 550ng/dl, at least about 600 ng/dl, at least about 650 ng/dl, at leastabout 700 ng/dl, at least about 750 ng/dl, at least about 800 ng/dl, atleast about 850 ng/dl, at least about 900 ng/dl, at least about 950ng/dl, at least about 1000 ng/dl, at least about 1050 ng/dl, and atleast about 1100 ng/dl. In an embodiment, the plasma level oftestosterone is maintained at a value selected from the group consistingof about 300 ng/dl or less, about 350 ng/dl or less, about 400 ng/dl orless, about 450 ng/dl or less, about 500 ng/dl or less, about 550 ng/dlor less, about 600 ng/dl or less, about 650 ng/dl or less, about 700ng/dl or less, about 750 ng/dl or less, about 800 ng/dl or less, about850 ng/dl or less, about 900 ng/dl or less, about 950 ng/dl or less,about 1000 ng/dl or less, about 1050 ng/dl or less, and about 1100 ng/dlor less.

In some embodiments, the level of testosterone is maintained asillustrated in FIG. 12. In an embodiment, the level of testosteronemaintained as illustrated in FIG. 12 is in a mammal. In an embodiment,the level of testosterone maintained as illustrated in FIG. 12 is in theserum of a mammal. In an embodiment, the mammal is a human.

B. Maintenance of Plasma Testosterone at Elevated Levels or WithinEffective Levels

In another embodiment, a method is provided herein for maintainingelevated plasma levels of testosterone in a mammal in need thereof. Incertain embodiments, this entails maintaining plasma levels from asubcutaneous dose at or above therapeutic levels (e.g., about 400 ng/dl,about 500 ng/dl, about 600 ng/dl, about 700 ng/dl, about 800 ng./ml,about 900 ng/dl) for an extended period of time. In some embodiments thelevel is maintained for a period of time that is longer than anintramuscular dose of the same volume and concentration. In anembodiment, the method comprises administering a composition comprisinga unit dose of testosterone (e.g., preservative-free) orpharmaceutically acceptable ester or salt thereof in a pharmaceuticallyacceptable carrier subcutaneously to a mammal, wherein afteradministration the plasma level of testosterone is maintained at anelevated level of up to about 1800 ng/dl for a period of time. In anembodiment, the time period for which plasma levels of testosterone aremaintained at an elevated level is referred to as a “Z2 time period”.

In some embodiments, the plasma level of testosterone is maintained atan elevated value selected from the group consisting of about 300 ng/dlto about 1800 ng/dl, about 400 ng/dl to about 1800 ng/dl, about 500ng/dl to about 1800 ng/dl, about 600 ng/dl to about 1800 ng/dl, about700 ng/dl to about 1800 ng/dl, about 800 ng/dl to about 1800 ng/dl,about 900 ng/dl to about 1800 ng/dl, about 1000 ng/dl to about 1800ng/dl, about 300 ng/dl to about 1100 ng/dl, about 400 ng/dl to about1100 ng/dl, about 500 ng/dl to about 1100 ng/dl, about 600 ng/dl toabout 1100 ng/dl, about 700 ng/dl to about 1100 ng/dl, about 800 ng/dlto about 1100 ng/dl, about 300 ng/dl to about 1800 ng/dl, about 300ng/dl to about 1700 ng/dl, about 300 ng/dl to about 1600 ng/dl, about300 ng/dl to about 1500 ng/dl, about 300 ng/dl to about 1400 ng/dl,about 300 ng/dl to about 1300 ng/dl, about 300 ng/dl to about 1200ng/dl, about 300 ng/dl to about 1100 ng/dl, about 300 ng/dl to about1000 ng/dl, about 300 ng/dl to about 900 ng/dl, about 300 ng/dl to about800 ng/dl, about 300 ng/dl to about 700 ng/dl, about 300 ng/dl to about600 ng/dl, about 300 ng/dl to about 500 ng/dl, or about 300 ng/dl toabout 400 ng/dl.

In certain embodiments, the blood plasma levels of testosterone aremaintained primarily between 400 and 1100 ng/dl, more typically between400 and 900 ng/dl, during the course of a treatment regimen. In certainembodiments, blood plasma levels at a value between about 400 and about1000 ng/dl is considered “therapeutically effective,” particularly forsteady state maintenance of testosterone levels during a treatmentregimen.

In an embodiment, a composition encompassed herein, when administeredaccording to the methods and the devices encompassed herein, maintainsthe plasma level of testosterone at an elevated level starting at about1 minute after administration and ending at about 1 month afteradministration. In an embodiment, a composition encompassed herein, whenadministered according to the methods and the devices encompassedherein, maintains the plasma level of testosterone at an elevated levelstarting at about 2 minutes after administration, or at about 3 minutes,about 4 minutes, about 5 minutes, about 10 minutes, about 20 minutes,about 30 minutes, about 45 minutes, about 60 minutes, about 2 hours,about 3 hours, about 4 hours, about 5 hours, about 6 hours about 7 hoursabout 8 hours about 9 hours, about 10 hours, about 11 hours, or about 12hours after administration, up to about 1 month after administration. Inan embodiment, a composition encompassed herein, when administeredaccording to the methods and the devices encompassed herein, maintainsthe plasma level of testosterone at an elevated level starting at about1 minute after administration and ending at about 25 days afteradministration, about 20 days after administration, about 15 days afteradministration, about 14 days after administration, about 13 days afteradministration, about 12 days after administration, about 11 days afteradministration, about 10 days after administration, about 9 days afteradministration, about 8 days after administration, about 7 days afteradministration, about 6 days after administration, about 5 days afteradministration, about 4 days after administration, about 3 days afteradministration, about 2 days after administration, about 1 day afteradministration, or about 0.5 days after administration.

C. Peak Plasma Concentration

In another embodiment, a method is provided herein for obtaining a peakplasma levels of testosterone in a mammal in need thereof. In anembodiment, a method is provided herein, using the compositions anddevices encompassed herein, to obtain a peak plasma concentration oftestosterone, after which the plasma concentration of testosteronedecreases to a therapeutically effective level for a period of time. Inanother embodiment, a method is provided herein, using the compositionsand devices encompassed herein, to obtain a peak plasma concentration oftestosterone, after which the plasma concentration of testosteronedecreases to an elevated level for a period of time.

In some embodiments, a peak level of testosterone is in the range ofabout 400 ng/dl to 2400 ng/dl, 500 ng/dl to 2400 ng/dl, 600 ng/dl to2400 ng/dl, 700 ng/dl to 2400 ng/dl, 800 ng/dl to 2400 ng/dl, 900 ng/dlto 2400 ng/dl, 1000 ng/dl to 2400 ng/dl, 1100 ng/dl to 2400 ng/dl, 1200ng/dl to 2400 ng/dl, 1300 ng/dl to 2400 ng/dl, 1400 ng/dl to 2400 ng/dl,1500 ng/dl to 2400 ng/dl, 1600 ng/dl to 2400 ng/dl, 1700 ng/dl to 2400ng/dl, 1800 ng/dl to 2400 ng/dl, 1900 ng/dl to 2400 ng/dl, 2000 ng/dl to2400 ng/dl, 2100 ng/dl to 2400 ng/dl, 2200 ng/dl to 2400 ng/dl, or about2300 ng/dl to 2400 ng/dl.

In another embodiment, a method is provided herein, using thecompositions and devices encompassed herein, to obtain a peak plasmaconcentration of testosterone, after which the plasma concentration oftestosterone decreases to lower-than-peak level for a period of time,the lower-than-peak level selected from about 300 ng/dl to about 1800ng/dl, about 400 ng/dl to about 1800 ng/dl, about 500 ng/dl to about1800 ng/dl, about 600 ng/dl to about 1800 ng/dl, about 700 ng/dl toabout 1800 ng/dl, about 800 ng/dl to about 1800 ng/dl, about 900 ng/dlto about 1800 ng/dl, about 1000 ng/dl to about 1800 ng/dl, about 300ng/dl to about 1100 ng/dl, about 400 ng/dl to about 1100 ng/dl, about500 ng/dl to about 1100 ng/dl, about 600 ng/dl to about 1100 ng/dl,about 700 ng/dl to about 1100 ng/dl, about 800 ng/dl to about 1100ng/dl, about 300 ng/dl to about 1800 ng/dl, about 300 ng/dl to about1700 ng/dl, about 300 ng/dl to about 1600 ng/dl, about 300 ng/dl toabout 1500 ng/dl, about 300 ng/dl to about 1400 ng/dl, about 300 ng/dlto about 1300 ng/dl, about 300 ng/dl to about 1200 ng/dl, about 300ng/dl to about 1100 ng/dl, about 300 ng/dl to about 1000 ng/dl, about300 ng/dl to about 900 ng/dl, about 300 ng/dl to about 800 ng/dl, about300 ng/dl to about 700 ng/dl, about 300 ng/dl to about 600 ng/dl, about300 ng/dl to about 500 ng/dl, or about 300 ng/dl to about 400 ng/dl.

In an embodiment, a method is provided herein, using the compositionsand devices encompassed herein, to obtain a peak plasma concentration oftestosterone, in which the peak plasma concentration of testosterone isachieved in about 48 hours, about 36 hours, about 24 hours, about 18hours, about 12 hours, about 11 hours, about 10 hours, about 9 hours,about 8 hours, about 7 hours, about 6 hours, about 5 hours, about 4hours, about 3 hours about 2 hours, about 1 hours, or about 0.5 hours.In an embodiment, the peak plasma concentration of testosterone isachieved in less than 48 hours, less than 36 hours, less than 24 hours,less than 18 hours, less than 12 hours, less than 11 hours, less than 10hours, less than 9 hours, less than 8 hours, less than 7 hours, lessthan 6 hours, less than 5 hours, less than 4 hours, less than 3 hoursless than 2 hours, less than 1 hours, or less than 0.5 hours.

D. Maintenance of Effective Levels of Testosterone After ComparativeDose Decreases Below Effective Levels

In an embodiment, it was surprisingly found that administration of atestosterone composition as encompassed herein provides a plasma levelof testosterone that is maintained at a therapeutically-effective levelfor a longer period of time than an equivalent dose of testosterone whenadministered to the same subject via one of a transdermal cream, gel orpatch or needle and syringe, intramuscularly, intradermally, orsubcutaneously. In an embodiment, at a time post-injection, atestosterone composition as encompassed herein (e.g., preservative-free)maintains a higher plasma concentration of testosterone than would aequivalent testosterone administered to the same subject via one of atransdermal cream, gel or patch or intramuscular injection by needle andsyringe over the same time period.

With reference to the figures and in particular FIG. 12, in oneembodiment, a method of administering testosterone comprisesadministering a composition comprising a unit dose of testosterone in apharmaceutically acceptable carrier subcutaneously to a mammal, whereinafter administration the plasma level of testosterone is maintainedbetween about 700 ng/dl and about 1800 ng/dl for a time period, “Z2”,wherein the plasma level of testosterone is also maintained betweenabout 300 ng/dl and about 1100 ng/dl for a time period, “Z3”, which isthe time after the plasma level of an equivalent intramuscularlyadministered dose drops below the plasma level of the subcutaneouslyadministered dose at the same time point post-administration.

In an embodiment, the plasma level of an equivalent intramuscularlyadministered dose drops below the plasma level of the subcutaneouslyadministered dose at about 1 day post-administration, at about 2 dayspost-administration, at about 3 days post-administration, at about 4days post-administration, at about 5 days post-administration, at about6 days post-administration, at about 7 days post-administration, atabout 8 days post-administration, at about 9 days post-administration,at about 10 days post-administration, at about 11 dayspost-administration, at about 12 days post-administration, at about 13days post-administration, or at about 14 days post-administration.

In an embodiment, and with reference to FIG. 12, post administration,the plasma level of testosterone is maintained, for a Z2 time period, ator between a level selected from: about 700 ng/dl and about 1800 ng/dl,about 750 ng/dl and about 1750 ng/dl, about 800 ng/dl and about 1700ng/dl, about 850 ng/dl and about 1650 ng/dl, about 900 ng/dl and about1600 ng/dl, about 950 ng/dl and about 1550 ng/dl, about 1000 ng/dl andabout 1500 ng/dl, about 1050 ng/dl and about 1450 ng/dl, about 1100ng/dl and about 1400 ng/dl, about 1150 ng/dl and about 1350 ng/dl, andabout 1200 ng/dl and about 1300 ng/dl.

In an embodiment, after administration, the plasma level of testosteroneis maintained, for a Z2 time period, at a level selected from the groupconsisting of about 700 ng/dl, about 750 ng/dl, about 800 ng/dl, about850 ng/dl, about 900 ng/dl, about 950 ng/dl, about 1000 ng/dl, about1050 ng/dl, about 1100 ng/dl, about 1150 ng/dl, about 1200 ng/dl, about1250 ng/dl, about 1300 ng/dl, about 1350 ng/dl, about 1400 ng/dl, about1450 ng/dl, about 1500 ng/dl, about 1550 ng/dl, about 1600 ng/dl, about1650 ng/dl, about 1700 mg/ml, about 1750 mg/ml, and about 1800 ng/dl.

In an embodiment, a Z2 time period is at least 1 hour, at least 2 hours,at least 3 hours, at least 4 hours, at least 5 hours, at least 6 hours,at least 12 hours, at least 18 hours, at least 24 hours, at least 36hours, at least 48 hours, or at least 72 hours.

In an embodiment, the plasma level of testosterone is maintained abovethe plasma level for testosterone administered via an equivalentintramuscularly administered dose at the same point in time, for a Z3time period. In another embodiment, the plasma level of testosterone ismaintained above therapeutic levels of testosterone for a Z3 timeperiod.

In yet another embodiment, and with reference to FIG. 12, afteradministration, the plasma level of testosterone is maintained for a Z3time period after the plasma level of an equivalent intramuscularlyadministered dose drops below the plasma level of the subcutaneouslyadministered dose at the same time point post-administration, at a valueselected from the group consisting of about 300 ng/dl to about 1100ng/dl, about 350 ng/dl to about 1050 ng/dl, about 400 ng/dl to about1000 ng/dl, about 450 ng/dl to about 950 ng/dl, about 500 ng/dl to about900 ng/dl, about 550 ng/dl to about 850 ng/dl, about 600 ng/dl to about800 ng/dl, about 650 ng/dl to about 750 ng/dl, about 675 ng/dl to about725 ng/dl and above about 300 ng/dl.

In an embodiment, after administration, the plasma level of testosteroneis maintained, for a Z3 time period after the plasma level of anequivalent intramuscularly administered dose drops below the plasmalevel of the subcutaneously administered dose at the same time pointpost-administration, at a value selected from the group consisting ofabout 300 ng/dl, about 350 ng/dl, about 400 ng/dl, about 450 ng/dl,about 500 ng/dl, about 550 ng/dl, about 600 ng/dl, about 650 ng/dl,about 700 ng/dl, about 750 ng/dl, about 800 ng/dl, about 850 ng/dl,about 900 ng/dl, about 950 ng/dl, about 1000 ng/dl, about 1050 ng/dl,and about 1100 ng/dl.

In an embodiment, a Z3 time period is at least 1 hour, at least 2 hours,at least 3 hours, at least 4 hours, at least 5 hours, at least 6 hours,at least 12 hours, at least 18 hours, at least 24 hours, at least 36hours, at least 48 hours, or at least 72 hours.

E. Maintenance of Effective Levels Over Multiple Treatments

Multiple treatments may include administration of two or more doses oftestosterone (e.g., preservative-free) according to a combination ofcompositions, devices, and methods encompassed herein. In an embodiment,the plasma level of testosterone in the Z3 time period is maintained attheraputically effective levels (e.g, a steady state at or above 300ng/dl or at or above about 400 ng/dl or other potential values asdescribed hereinabove). In an embodiment, the plasma level oftestosterone in the Z3 time period is maintained at or above atherapeutically effective level while a second dose is administered. Inan embodiment, the plasma level of testosterone in the Z3 time period ismaintained above a therapeutically effective level until a second doseis administered. In an embodiment, the plasma level of testosterone inthe Z3 time period is maintained at an elevated level. In an embodiment,the plasma level of testosterone in the Z3 time period is maintained ata level between 300 ng/dl and 700 ng/dl, between 300 ng/dl and 1100ng/dl, between 300 ng/dl and 1800 ng/dl, between 700 ng/dl and 1100ng/dl, between 700 ng/dl and 1800 ng/dl, or between 1100 ng/dl and 1800ng/dl, and/or above about 300 ng/dl, until a second dose isadministered, whenafter the blood levels of testosterone will likelyincrease again in accordance with well understood pharmacokinetics.

In an embodiment, administration of a testosterone composition asencompassed herein provides a stimulatory effect immediately afterinjection, such that the plasma level of testosterone is above a plasmatherapeutic level of testosterone for a period of time, but not so highas to be toxic to the subject. In an embodiment, stimulatory levels ofplasma testosterone can be detected by measuring the plasma levels oftestosterone. In another embodiment, stimulatory levels of testosteronecan be detected by measuring a surrogate for plasma testosterone levels,such as, but not limited to, one or more endocrinology profiles of thesubject to which the testosterone was administered. In an embodiment,endocrinology markers include, but are not limited to, red blood cellproliferation and/or other markers indicative of hormonal function.

F. Stimulatory Effect

In another embodiment, administration of a testosterone composition asencompassed herein provides a stimulatory effect immediately afterinjection, such that the plasma level of testosterone is above a plasmatherapeutic level of testosterone for a period of time, but not so highas to be toxic to the subject. After the plasma levels of testosteronefall from the stimulatory levels, the plasma levels of testosterone arewithin the therapeutically effective levels as discussed herein. In anembodiment, administration of a testosterone composition as encompassedherein provides a minimal stimulatory effect immediately afterinjection, such that the plasma level of testosterone is above a plasmatherapeutic level of testosterone for a period of time, but not so highas to be toxic to the subject, after which the plasma levels oftestosterone are within the therapeutically effective levels asdiscussed herein. In an embodiment, administration of a testosteronecomposition as encompassed herein provides no stimulatory effectimmediately after injection, and the plasma level of testosterone ismaintained at a therapeutically effective level as discussed herein.

In an embodiment, testosterone administered to a subject in accordancewith the methods of the invention provides pharmacokinetics, includingsystemic bioavailability, that has diminished pharmacokinetics,including systemic bioavailability, of testosterone when the same doseof testosterone is administered to said subject using needle andsyringe, intramuscularly or subcutaneously.

EXAMPLES Example 1: Injection of Viscous Fluid Compositions

A formulation was prepared including arachis oil and 10% benzyl alcoholand an active pharmaceutical ingredient based on testosterone. Thisformulation had a viscosity of 1000 cps. An MJ-7 needlefree injectiondevice made by Antares Pharma was used to administer 0.5 ml of theformulation. The study used the following device power and needle-freesyringe orifice settings to achieve needle-free injection of and arachisoil-10% benzyl alcohol solution.

For achieving intramuscular injections, the injection device was poweredwith a spring having a spring force of 100 lbs and was equipped with aneedle-free syringe having an orifice of 0.36 mm (0.014″) diameter.

For achieving subcutaneous injections, the injection device was poweredwith a spring having a spring force of 85 lbs and was equipped with aneedle-free syringe having an orifice of 0.28 mm (0.011″) diameter.

Results are as follows:

TABLE 3 Intramuscular injections. Intramuscular injections CompleteIncomplete, or wet, injections Needle free 40 83% 8 17% Needle andsyringe with IM 47 98% 1  2% needle

TABLE 4 Subcutaneous injections Subcutaneous injections CompleteIncomplete, or wet, injections Needle free 23 48% 25 52% Needle andsyringe with SC 22 46% 26 54% needle

In an embodiment, it will be understood that when mini-needle devicesare used instead of needless injection devices, the needle bores wouldbe on the same order as the orifices of the needle-free devices.

Example 2: Comparison of Cavg and C max for Various TestosteroneFormulations and Methods of Delivery

Experimental protocols and references for available data on the Cavg-Cmax can be found in package insert labels of Androgel 1% (NDA No.021015), Androgel 1.62% (NDA No. 022309), Testim (NDA No. 021454) andAxiron (NDA No. 022504).

TABLE 5 Comparison of Cavg and Cmax calculated for Androgel and Testimat various concentrations. Agel Agel Agel Agel Testim Testim 20.25 40.560.75 81 50 100 CaV 386 474 513 432 365 612 Cmax 562 715 839 649 538 897Cmax/Cav 1.455959 1.508439 1.635478 1.502315 1.473973 1.465686

TABLE 6 Comparison of Cavg and Cmax calculated for Axiron andtestosterone enanthate at various concentrations. AX 60 AX 90 AX 120 TE100 TE 200 Cav 506 415 390 1021 924 Cmax 839 664 658 1299 1315 Cmax/Cav1.658103 1.6 1.687179 1.272282 1.42316

Example 3: Pharmacokinetic Study of Testosterone by Injection inCastrated Minipigs

The objective of this study was to evaluate the pharmacokinetics oftestosterone (Antares QS Autoinjector Device with 10 mm injection depth)when administered via injection to castrated minipigs on Days 1 and 15.

The test system included minipigs of the Yucatan strain. Castrated maleminipigs were obtained from Sinclair Research Center, Inc., Windham, Me.Minipigs were 15 to 20 weeks old, and the target Weight at theinitiation of dosing was 20 to 25 kg. The Yucatan minipig was chosen asthe animal model for this study as it is a preferred non-rodent speciesfor preclinical toxicity testing by regulatory agencies. Housing andcare was as specified in the USDA Animal Welfare Act (9 CFR, Parts 1, 2,and 3) and as described in the Guide for the Care and Use of LaboratoryAnimals from the National Research Council. The animals wereindividually housed in swine pens/cages.

The experiment was designed as follows:

No. of male Group No. animals Test material Dose volume 1 3testosterone, 0.5 ml 100 mg 2 3 testosterone, 0.5 ml 200 mg Testarticles used for injection of animals included: test article 1,testosterone enanthate at 100 mg/ml in pre-filled syringes; test article2, testosterone enanthate at 200 mg/ml in pre-filled syringes; testarticle 3, testosterone enanthate at 100 mg/ml in vials; and testarticle 4, testosterone enanthate at 200 mg/ml in vials.

On Day 1, dose material was delivered by a pre-loaded Antares QSAutoinjector Device (see. e.g., co-pending application Ser. No.61/763,395, which is incorporated by reference). On Day 15, dosematerial was delivered by needle and syringe. Test Articles 1 and 2 wereadministered to the appropriate animals via injection using amini-needle auto-injector into the scapular region on Day 1 to TestSite 1. The animal's dorsal surface area was clipped free of hair with asmall animal clipper before the first dose and as often as necessarythereafter to allow for clear visualization of the test site. Care wastaken during the clipping procedure to avoid abrasion of the skin. Theinjection site (approximately 2 cm×2 cm) was delineated with anindelible marker and remarked as necessary thereafter. Test Articles 3and 4 were administered to the appropriate animals via intramuscularinjection using a 1 mL syringe with a 27 gauge×1 inch needle into theproximal portion of the hindlimb to an approximate depth of ¾ inch onDay 15 to Test Site 2. The animal's proximal hindlimb was clipped freeof hair with a small animal clipper before the first dose and as oftenas necessary thereafter to allow for clear visualization of the testsite. Care was taken during the clipping procedure to avoid abrasion ofthe skin. The injection site (approximately 2 cm×2 cm) was delineatedwith an indelible marker and remarked as necessary thereafter. Followingall Day 22 study observations and bioanalytical sample collection, theanimals (including the alternate male pig) were assigned to theexploratory trial phase of this study. The animal's dorsal surface areawas clipped free of hair with a small animal clipper before the firstdose and as often as necessary thereafter to allow for clearvisualization of the test site. The QS Autoinjector Device was used todeliver a 0.5 mL dose of dye via injection, into naive scapular area.The naïve proximal portion of the hindlimb was injected with a 0.5 mLdose of dye via intramuscular injection using a 27 gauge×1 inch needleand syringe. The injection sites (approximately 2 cm×2 cm) weredelineated with an indelible marker. Following dose administration, theanimals (including the alternate animal) were subjected to euthanasiaand examination. The first day of dosing was designated as Study Day 1.

An injectable route of exposure was selected because this is theintended route of human exposure. An injection depth of 10 mm wasinvestigated as part of this study. Dose levels of 100 mg and 200 mgwere determined to provide comparison of the intramuscular route ofadministration via autoinjector and needle and syringe, fortoxicokinetic purposes. The intramuscular route was selected for furtherinvestigation, as this route resulted in less material loss postinjection than subcutaneous administration based on macroscopicobservations. Doses lower than 100 mg may not have provided necessarycirculating concentrations, while doses over 200 mg were not required.Dose levels and weekly dose regimen were based on the following suppliedreference document “Daily Testosterone and Gonadotropin Levels AreSimilar in Azoospermic and Nonazoospermic Normal Men Administered WeeklyTestosterone: Implications for Male contraceptive Development” Journalof Andrology Vol. 22, No. 6 November/December 2001.

The injection sites of each animal were observed on the day ofrandomization and daily from Days 1 to 22 (at approximately 1 and 4hours postdose on the days of dosing and once daily on non-dosing days).Particular attention was paid to the injection sites regarding erythema,edema, and any other additional adverse findings.

Blood was collected by venipuncture of the vena cava. Samples werecollected according to the following table:

TK Sample Collection Sample Collection Time Points Schedule Group No.(Time Post Dose) on Days 1 and 15 0 hr 3 hr 6 hr 12 hr 24 hr 48 hr 72 hr96 hr 168 hr 1 X X X X X X X X 2 X X X X X X X X X = sample to becollected; — = not applicable. (zero hour sample collected beforedosing) Target Volume: 3.0 mL Anticoagulant: None Processing: To serum

Blood was collected by venipuncture of the vena cava. Samples werecollected according to the following table: Samples were allowed to clotat room temperature for at least 30 minutes before centrifugation.

The samples were centrifuged at ambient temperature at 1800×g. Theresulting serum was separated into 3 aliquots of approximately 0.5 mLeach for analysis. One aliquot was designated for testosterone and DHTanalysis, 1 aliquot for analysis of Sex Hormone Binding Globulin (SHBG),and 1 aliquot for determination of total serum albumin. The serumsamples were transferred into uniquely labeled polypropylene tubes andstored frozen in a freezer set to maintain −70° C. Samples to beanalyzed were shipped overnight on dry ice to the bioanalyticallaboratory for analysis.

One set of serum samples was analyzed for concentration of totaltestosterone using a validated analytical procedure. The samplescollected for sex hormone binding globulin (SHBG) and serum albumin willnot be analyzed at this time. DHT was not analyzed for this study.Testosterone analysis was performed by LCMS using a method validatedunder Charles River Study 20027106. Data collection was performed usingAnalyst from MDS Sciex. Statistical analyses including regressionanalysis and descriptive statistics including arithmetic means andstandard deviations, accuracy and precision were performed using WatsonLaboratory Information Management System (LIMS) and Microsoft Excel.

Toxicokinetic parameters were estimated using Watson LaboratoryInformation Management System (LIMS) and Microsoft Excel. Anon-compartmental approach consistent with the subcutaneous andintramuscular route of administration was used for parameter estimation.Individual and mean PK parameters were reported and included C max, Tmax, and AUC0-last. When data permitted, the slope of the terminalelimination phase of each concentration versus time curve was determinedby log-linear regression, and the following additional parameters werealso estimated: AUCO-inf, terminal elimination half-life. All parameterswere generated from testosterone (total) concentrations in serum fromDays 1 and 15 unless otherwise stated. Parameters were estimated usingsampling times relative to the start of each dose administration.

FIGS. 13-19 illustrate, in part, the results of the studies described inExample 3, for various testosterone enanthate concentrations deliveredby either auto-injector or traditional needle and syringe methods.

No animals died during the course of the study. There were no testarticle-related clinical signs during the study. Sporadic occurrences ofscabs, reddened areas, or mechanical injury were noted during the study.These were considered background findings associated with the animalrubbing against the cage or areas that were irritated during dosingprocedures while the animals were in the sling. One animal was noted asstruggling during dosing on Day 15; however, this did not appear toaffect dose administration.

A small amount of material injected at each test site leaked from theinjection site once the device or needle was removed. The amount ofleakage was comparable across the sites and animals. Additionally,redness was noted at the injection site after injection across the testsites. There were no additional dermal changes noted during the studyinterval.

No test article-related effects on body weight occurred during thestudy. All animals showed an increase in weight from their startingweight during the study. The results of the trial with the injection ofdye in sesame oil resulted in verification of subcutaneous delivery inall animals that received a dose from the QS Autoinjector Device.Conventional administration via needle and syringe administrationresulted in intramuscular delivery of the dye, except in 1 animal thathad subcutaneous delivery with a dark area in the muscle.

Each and every reference herein is incorporated by reference in itsentirety. The entire disclosure of U.S. Pat. Nos. 8,021,335, 7,776,015,and 6,391,003 and PCT application publication WO 2010/108116 are alsohereby incorporated herein by reference thereto as if fully set forthherein.

It will be appreciated by those skilled in the art that changes could bemade to the exemplary embodiments described above without departing fromthe broad inventive concept thereof. It is understood, therefore, thatthis invention is not limited to the exemplary embodiments described,but it is intended to cover modifications within the spirit and scope ofthe present invention as defined by the claims. For example, specificfeatures of the exemplary embodiments may or may not be part of theclaimed invention and features of the disclosed embodiments may becombined.

It is to be understood that at least some of the figures anddescriptions of the invention have been simplified to focus on elementsthat are relevant for a clear understanding of the invention, whileeliminating, for purposes of clarity, other elements that those ofordinary skill in the art will appreciate may also comprise a portion ofthe invention. However, because such elements are well known in the art,and because they do not necessarily facilitate a better understanding ofthe invention, a description of such elements is not provided herein.

Further, to the extent that the method does not rely on the particularorder of steps set forth herein, the particular order of the stepsshould not be construed as limitation on the claims. The claims directedto the method of the present invention should not be limited to theperformance of their steps in the order written, and one skilled in theart can readily appreciate that the steps may be varied and still remainwithin the spirit and scope of the present invention.

1. A injection device, comprising: a housing member having a distal endand a proximal end; a chamber disposed within the housing memberconfigured to hold an amount of a preservative-free medicamentcomprising testosterone; a needle operatively associated with thechamber and having a length sufficient to deliver the medicament to aninjection site at a depth below a patient's skin sufficient to minimizeleak-back; a plunger movable within the chamber; and a force generatingsource capable of providing sufficient force on the plunger to eject atleast a portion of the medicament from the chamber through the needle inless than about 20 seconds.
 2. The injection device of claim 1, whereinthe injection site is subcutaneous.
 3. The injection device of claim 1,wherein the force on the plunger is configured to eject at least aportion of the medicament from the chamber through the needle in lessthan about 15 seconds
 4. The injection device of claim 1, wherein theforce on the plunger is configured to eject all of the medicament fromthe chamber through the needle in less than about 15 seconds.
 5. Theinjection device of claim 1, wherein the force on the plunger isconfigured to eject all of the medicament from the chamber through theneedle in less than about 10 seconds.
 6. The injection device of claim1, wherein the needle length is greater than about 5 mm.
 7. Theinjection device of claim 1, wherein the needle length is less thanabout 20 mm.
 8. The injection device of claim 1, wherein the needlelength is between about 5 and 12 mm.
 9. The injection device of claim 1,wherein the needle gauge is 27 gauge.
 10. The injection device of claim1, wherein the needle gauge is 25 gauge to 30 gauge.
 11. The injectiondevice of claim 1, wherein the needle is a thin-walled needle.
 12. Theinjection device of claim 1, wherein when used, there is substantiallyno leak-back.
 13. The injection device of claim 1, wherein when used,there is no leak-back.
 14. The injection device of claim 1, wherein whenused, there is no leak-back in about 95% of the injections.
 15. Theinjection device of claim 1, wherein when used, the amount of leak backis less than about 15% of the total injected volume of medicament. 16.The injection device of claim 1, wherein when used, the amount of leakback is no more than the amount of leak back selected from the groupconsisting of about 0.05% to about 15% of the total injected volume ofmedicament, about 0.1% to about 12.5% of the total injected volume ofmedicament, about 0.2% to about 10% of the total injected volume ofmedicament, about 0.3% to about 7.5% of the total injected volume ofmedicament, about 0.4% to about 5% of the total injected volume ofmedicament, about 0.5% to about 3% of the total injected volume ofmedicament, about 0.6% to about 2% of the total injected volume ofmedicament, about 0.7% to about 1% of the total injected volume ofmedicament.
 17. The injection device of claim 1, wherein when used, theamount of leak back is less than about 15% of the total weight of theinjected medicament.
 18. The injection device of claim 1, wherein whenused, the amount of leak back is no more than the amount of leak backselected from the group consisting of about 0.1% to about 15% of thetotal weight of the injected medicament, about 0.5% to about 12.5% ofthe total weight of the injected medicament, about 1% to about 10% ofthe total weight of the injected medicament, about 2% to about 7.5% ofthe total weight of the injected medicament, and about 3% to about 5% ofthe total weight of the injected medicament.
 19. The injection device ofclaim 1, further comprising a collar surrounding the needle and defininga collar cavity, the collar having a peripheral and forwardskin-contacting surface that surrounds, is discontinuous, and isradially spaced from the needle and injection site by an area that issufficiently large to allow a patient's skin to move into the collarcavity to properly position the needle to penetrate the patient forintradermal delivery of the substance to the injection site to allowspread of the injected substance under the skin while inhibiting orpreventing backpressure within the skin from forcing the substance outthrough the injection site.
 20. An injection device comprising: ahousing; a cartridge container disposed within the housing; a cartridgereceived within the cartridge container, the cartridge having at leastone opening therein and containing a medicament comprising testosterone,the medicament rearwardly confined by a plunger, wherein the cartridgeincludes a needle assembly to dispense the medicament there through, theneedle assembly comprising a needle and a non-removable protectiveneedle sheath, the needle having a length sufficient to deliver themedicament to an injection site at a depth below a patient's skinsufficient to minimize leak-back; an actuation assembly providing astored energy source capable of being released to drive the needlethrough the protective needle sheath and to drive the plunger within thecartridge to dispense the medicament through the needle assembly, thestored energy source providing a force sufficient to eject at least aportion of the medicament from the chamber through the needle in lessthan about 20 seconds; a needle cover received within the housing, theneedle cover having an opening formed therein to permit the passage ofthe needle assembly there through during a medicament dispensingoperation, the needle cover having a first locked position whereby theneedle cover is in a locked retracted position prior to activation ofthe auto-injector, the needle cover having a second locked positionwhereby the needle cover is in a locked extended position afteroperation of the auto-injector; a first locking assembly that holds theneedle cover in the first locked position; and a second locking assemblythat holds the needle cover in the second locked position. 21.-48.(canceled)